2.1 ESCs in NIR varieties

The first work to systematically explore the occurrence of ESCs in NIR varieties is Renzi & Vanelli (Reference Renzi, Vanelli, Benincà, Cortelazzo, Prosdocimi, Vanelli and Zamboni1983). They considered three types of impersonal constructions: weather verbs (e.g. it is raining), existentials (e.g. there is a girl), and impersonal deontics (e.g. it is necessary that). Despite being based on a rather small sample of varieties (30) and respondents (one or two informants per variety), Renzi & Vanelli’s survey captured some trends: the NIR varieties that had ESCs in all three impersonal contexts also had subject clitics with both preverbal and postverbal subjects and displayed full-fledged paradigms.Footnote ³ This is the case, for example, of the variety of Monno, as in (3) (data from Pescarini & Loporcaro Reference Pescarini, Loporcaro, Ledgeway and Maiden2022: 153–154): here, both preverbal (3a) and postverbal (Example 3b) subject is mandatorily doubled by the subject clitic and ESCs occur in impersonal constructions (3c).

Other varieties had defective paradigms. This is the case of the variety of Trieste (Friuli) (4), where the subject proclitic le is optional with preverbal subjects (4a), but mostly excluded with postverbal subjects (4b), and there is no ESC (4c) (data from Pescarini & Loporcaro Reference Pescarini, Loporcaro, Ledgeway and Maiden2022: 153–154).

Renzi & Vanelli (Reference Renzi, Vanelli, Benincà, Cortelazzo, Prosdocimi, Vanelli and Zamboni1983) also noted that – overall – ESCs are mostly found with weather verbs, while they are scarcely attested with impersonal deontics. Based on their findings, they designed an implicational scale according to which having ESCs with weather verbs is a prerequisite for having ESCs in all other impersonal constructions (Renzi & Vanelli Reference Renzi, Vanelli, Benincà, Cortelazzo, Prosdocimi, Vanelli and Zamboni1983: 135–136).

Capitalizing on Renzi & Vanelli’s work, Pescarini (Reference Pescarini2012; Reference Pescarini2014; Reference Pescarini, Ledgeway and Maiden2016) explored the distribution of ESCs in a sample of 140 NIR varieties that included two additional impersonal contexts, namely, epistemic (e.g. it seems that) and impersonal si (e.g. one says that) constructions. The implicational scale proposed by Pescarini (Reference Pescarini2012; Reference Pescarini2014; Reference Pescarini, Ledgeway and Maiden2016) (cf. 5) resonates with Renzi & Vanelli’s (Reference Renzi, Vanelli, Benincà, Cortelazzo, Prosdocimi, Vanelli and Zamboni1983): ESCs are more likely to occur with weather verbs. This possibility decreases as one moves to the right of the scale: ESCs ‘are less common in other impersonal contexts like raising constructions, existential constructions, impersonal si constructions, and in combination with the impersonal modal of necessity’ (Pescarini Reference Pescarini, Ledgeway and Maiden2016: 747). This would imply a higher quantity of varieties having ESCs with weather verbs (68% of Pescarini’s sample) than having ESCs with other constructions (existentials: 59%; epistemics: 54%; impersonal si: 32%; impersonal deontics: 22%); and the distribution of ESCs in each variety would follow an implicational scale. NIR varieties that admit ESCs with one construction require that ESCs also occur with all other constructions to its left in the scale.

Another milestone in research on subject clitics is Manzini & Savoia (Reference Manzini and Savoia2005, I: Ch. 2). It included data from 187 Italo-Romance varieties (as counted by Pescarini Reference Pescarini, Ledgeway and Maiden2016) and involved three types of impersonal context: weather verbs, constructions with a postverbal phrasal subject that does not agree with the verb (corresponding to, e.g. *here comes the boys), and impersonal constructions that take a clause as a complement (e.g. it is better that). The authors merely observed that NIR varieties show different behaviors: some admit ESCs in all three contexts, others only in some (Manzini & Savoia Reference Manzini and Savoia2005, I: 193–191). Some of the data in Manzini & Savoia seem not to comply with Pescarini’s (Reference Pescarini2012; Reference Pescarini2014; Reference Pescarini, Ledgeway and Maiden2016) scale. For example, in some varieties, ESCs do not occur with weather verbs and yet they occur in other contexts. This is the case of the variety of Povegliano (Veneto), exemplified in (6) (data from Manzini & Savoia Reference Manzini and Savoia2005, I: 193):

Recently, Pescarini (Reference Pescarini2022) statistically analyzed data from 350 data points. While this is noteworthy, the database is an aggregation of the data from Manzini & Savoia (Reference Manzini and Savoia2005) and the ASIt database.Footnote ⁴

The works hitherto cited certainly give an account of the diatopic variation and complexity of the phenomenon. Data were collected using questionnaires (sometimes written questionnaires) from generally no more than one or two (rarely, up to five) informants per data point. Since the purpose was to delineate the systems of ESC in the NIR varieties under investigation, the selected informants plausibly represented their conservative incarnations. There is a downside to this approach, however: empirical evidence gathered this way does not allow us to (a) capture sociolinguistic variation and (b) understand whether the absence of ESCs in a given context of a given variety is systematic or due to idiolectal variation. As Ferrarotti (Reference Ferrarotti, Cruschina, Ledgeway and Remberger2019: 111) puts it, if an ESC ‘does not appear in a given context, that is not necessarily to say that it is unacceptable, for it may simply have been omitted’.

To the best of our knowledge, the only investigation into the topic that involves a representative population sample is Casalicchio & Frasson’s (Reference Casalicchio, Frasson, Chilà and Angelis2018) survey on the four Venetan varieties of Paduan, Trevigiano, Venetian, and Vicentino. The authors reported that, while 91% of the respondents judged the absence of ESCs such as in Trevigiano ø ze drio nevegar ‘it is snowing’ as correct, a substantial portion of respondents (42.1%) did accept ESCs with this construction (cf. Trevigiano el=ze drio piovar ‘it is raining’). The authors interpreted this result as an overextension of the syntactic rule on the use of subject clitics. However, Casalicchio & Frasson’s (Reference Casalicchio, Frasson, Chilà and Angelis2018) study is problematic in two respects: first, it deals with just one type of impersonal construction, namely, weather verbs, leaving out at least five other relevant contexts that can license the occurrence of ESCs; second, it used four questionnaire variants, based on the varieties of the four towns of Padua, Treviso, Venice, and Vicenza; however, the questionnaires were administered to speakers living in all municipalities of these provinces. This procedure amounts to largely ignoring the extant diatopic variation.

2.2 Change in the sociolinguistic environment

For more than 70 years now, a heavy sociolinguistic change has invested the entire Italo-Romance landscape (in Italy). After the Second World War, several factors boosted the use of (mainly Tuscan-based) standard Italian across the population. One of these factors was the purchase of televisions on a large scale, made possible in the wake of the ‘economic boom’ enduring until the end of the 1960s, which sustained the population’s exposure to the standard variety used on national television programs. As a result of this exponentially increased exposure, the speakers’ competence in local varieties (generally referred to as ‘dialects’) has changed dramatically over the past 70 years. The contact between the dialects and the standard has had bidirectional effects: On the one hand, dialect-dominant speakers have imposed traits of their local Italo-Romance varieties onto Italian, leading to the emergence of regional Italian varieties (for details, cf. Cerruti Reference Cerruti2011); on the other, standard Italian has ousted the local Italo-Romance varieties, gradually replacing them, and establishing itself as the dominant language, and this came along with a general contraction of dialect speakers in the Italian peninsula. As statistics reported in De Mauro (Reference De Mauro2014: 113) show, the use of dialects as a sole means of communication decreased from 64.0% in 1955 to 5.4% in 2006. At the same time, the percentage of people using Italian as a sole means of communication increased from 18.0% in 1955 to 45.5% in 2006. The most recent data (ISTAT 2017) from 2015 indicate that in the domain ‘in the family,’ 45.9% of the population (from age 6 onwards) predominantly use Italian, while 14.0% predominantly use a dialect, and 32.2% use both Italian and a dialect. Similar dynamics are found in the domains ‘with friends’ and ‘with strangers’.

The exclusive or predominant use of local varieties decreases in all age groups: as of 2015, 32.0% of speakers aged 75 or above state that they exclusively or predominantly speak dialect in the family, while in 2006, it was 37.1%. From a diastratic viewpoint, dialect use in the family and with friends is maintained to a larger extent among speakers with a low educational qualification, irrespective of age: among speakers with 8 years of schooling, 24.8% exclusively use dialect in the family and 33.7% with friends, whereas among speakers with a bachelor or a higher degree, the figures are 3.1% in the family and 2.7% with friends.

However, this decrease has not affected all areas of the peninsula homogeneously. The ISTAT (2017) 2015 data show that Veneto, despite a progressive increase in the use of Italian, ranks among the regions in which the use of dialects is still relatively high: in the domain ‘in the family,’ 30.6% of the population (from age 6 onwards) predominantly use a dialect, while, for example, in neighboring Lombardy, it is 5.6%. If we lump together the declared sole or predominant use of dialect in the family with that of both Italian and dialect, we get 62.0% in Veneto versus 31.7% in Lombardy. Nowadays, Veneto is characterized by a situation of diglossia involving standard Italian and local varieties, which are vital and spoken on a daily basis: Older generations (aged 80 onwards) tend to have a dialect as L1 and the dominant language, both qualitatively (for example, in terms of proficiency) and quantitatively (in terms of social domains in which it is spoken), while in younger generations, standard Italian is rather the dominant language.

3.1 Research questions and hypotheses

In this case study, we move from the following sociolinguistic and contact-theoretical considerations: (a) Starting from the 1950s, standard Italian has increasingly become the dominant language in the wake of the massive sociolinguistic change that has invested Italy, even in areas such as Veneto in which Italo-Romance varieties have been more resilient. (b) In language contact, the source of change is the (individually or socially) dominant language, which might encroach upon the structure of the recipient language in a systematic way. (c) However, contact does not necessarily lead to change. As a matter of fact, the very prerequisite for contact-induced change to happen is the existence of divergent structures (cf. Gardani Reference Gardani, Ledgeway and Maiden2022: 847–850). The presence of ESCs in Opitergino and their absence in its contact language, standard Italian, represents precisely such a case of structural incongruence, which can – though need not – lead to change.

Based on this, we pursue the following main research question (RQ1): Has the contact with standard Italian induced change in the ESC system of Opitergino? At this point, it should be stressed that ‘deterministic and absolute predictions’ (Thomason Reference Thomason2000: 175) on the linguistic outcome of language contact are impossible to make – at least, as concerns single contact settings (whereas making predictions over crosslinguistic samples is a viable option, as shown, e.g. by Gardani Reference Gardani2008; Reference Gardani, Johanson and Robbeets2012). Instead, we can formulate hypotheses about what is reasonable to expect. In our specific case, the predominance of standard Italian over local varieties and its being the moderately dominant language in large parts of the population prompts us to discard the null hypothesis and to deem it probable that (H1) some degree of contact-induced change has indeed occurred.

Secondly, if change has occurred, (RQ2) what sort of change is it reasonable to expect? In that respect, we cannot sufficiently rely on results from previous investigations, as research on the behavior of clitics in language contact is generally meager.Footnote ⁵ A likely outcome could be a convergence towards the structure of the dominant language, standard Italian. However, the interplay of sociological and structural factors provides an extra layer of intricacy. The sociolinguistic structure of a speech community is known to play a decisive role in determining not just the directionality of change but also – crucially – the extent to which structural change can occur (cf. Weinreich’s Reference Weinreich1953: 112 ‘twin approach’). In areas in which Italian is clearly the dominant language (such as Lombardy), we could – in principle – expect a net convergence of Italo-Romance varieties towards Italian, resulting, say, in the loss of ESC.Footnote ⁶ But in Oderzo, the sociolinguistic dynamics are different; hence, such a clear-cut outcome is less probable: Speakers of Opitergino are proficient speakers,Footnote ⁷ and proficient bilinguals tend to be more preserving than nonproficient speakers. Based on these observations, we expect that (H2) contact has produced slight structural convergence towards standard Italian not resulting in loss.

Thirdly, if convergence has occurred, where and how did it become manifest? We focus on syntactic change, specifically on the obligatoriness of rules, which we understand as context-sensitivity. We ask (RQ3): Does obligatoriness (vs optionality) plays a role in contact-induced change? Note that this question has been largely disregarded by theoretical debates on language contact, a remarkable exception being Thomas (Reference Thomas2012). The key element here is that rule optionality may generate a certain amount of uncertainty. Matter-of-factly, Thomas (Reference Thomas2012: 208) ‘found that like monolinguals, bilinguals tend to limit optional grammars, but do so in different ways according to the unique cognitive and experiential factors associated with their age of exposure to bilingualism’. A possible speakers’ reaction to uncertainty is reducing it, which can be implemented via either obliteration of optionality (optional rules become obligatory) or rule generalization (‘removing a condition from a rule,’ according to Harris & Campbell Reference Harris and Campbell1995: 102). As we will see (Section 3.2), in Opitergino, ESCs are context-sensitive in declarative clauses, whereas they are context-insensitive in interrogative clauses. We therefore expect that (H3) change has affected ESCs in the domain of declarative clauses to a greater extent than in interrogative clauses.

Besides, we cannot rule out secondary ‘internal rearrangements’ (Heath Reference Heath1984: 368; called ‘later changes’ in Thomason Reference Thomason2001: 62), but any hypothesis to this effect would be impressionistic.

To test the three hypotheses, in the remainder of the paper, we (a) provide a baseline of ESCs in conservative Opitergino (Section 3.2), (b) present the results of an online survey we conducted in 2022 with 100 informants (Section 4), and (c) compare them (Section 5).

3.2 The baseline

There are virtually no studies focusing on Opitergino. While some studies exist on other varieties belonging to Liventino, the dialect group to which Opitergino belongs (Zamboni Reference Zamboni1974; Reference Zamboni and Cortelazzo1979), and more generally on northern Venetan dialects (also including Trevigiano, Feltrino, and Bellunese), the documentation of the Liventino varieties is scarce. The oldest Opitergino text we found is a short text by Francesco Carlo Gasparinetti from the 19th century, recorded in Papanti (Reference Papanti1875: 515); unfortunately, this text does not contain any impersonal construction, thus no ESCs. There are a few more texts in Opitergino, but besides their being poems, they do not match the chronological depth necessary to build the baseline (authors were born after the 1960s and, in some cases, left Veneto in early childhood, e.g. Franzin Reference Franzin2013). Therefore, we set to establish our baseline ourselves, aiming at the conservative Opitergino spoken before the widespread Opitergino/standard Italian bilingualism of recent decades. Relying on an apparent time approach (cf. Labov Reference Labov1963), we extracted the baseline from the speech of elder people who speak Opitergino as an L1 (while Italian is their L2). To create the relevant baseline, we conducted interviews with four speakers (m = 2) born before 1942, as reported in Table 1.

Table 1 Demographic profile of the baseline informants (conservative Opitergino).

First, we put together the paradigms of strong personal subject pronouns and subject clitics (both proclitics and enclitics). They are given in Table 2. We also determined that ESCs exist in Opitergino. They have the same forms of the III m.sg, namely, proclitic el and l (the latter occurring before copular é) in declarative sentences (henceforth, ‘declaratives’), and enclitic eo and o in interrogative sentences (henceforth, ‘interrogatives’).

Table 2 The system of subject pronouns in Opitergino.

As Table 2 shows, the paradigm of subject proclitics (found in declarative clauses) is defective: first singular, first plural, and second plural persons are lacking. This is in line with the characteristics of the Liventino group (Zamboni Reference Zamboni and Cortelazzo1979). By contrast, the paradigm of subject enclitics (in interrogative clauses) is not defective. This asymmetry between the proclitic and enclitic paradigms is also a common feature of almost all Venetan varieties (Zamboni Reference Zamboni1974: 50). According to some authors (Renzi & Vanelli Reference Renzi, Vanelli, Benincà, Cortelazzo, Prosdocimi, Vanelli and Zamboni1983; Pescarini Reference Pescarini2012; Reference Pescarini2014; Reference Pescarini, Ledgeway and Maiden2016; cf. intra Section 2), NIR varieties with defective proclitic paradigm are expected to have no obligatory subject doubling and no ESCs.Footnote ⁸ However, in Opitergino, subject clitics are mandatory with preverbal subjects, that is, doubling does occur (7a), while they are mostly excluded in the presence of postverbal subjects (cf. e fòje in 7b).

In a second step, we investigated which impersonal contexts license the presence of ESCs in Opitergino. Capitalizing on the studies mentioned in Section 2, we considered the following six constructions:Footnote ⁹

• – Subjectless Predicative Copular (SPC) construction (e.g. Italian è una bambina ‘it is a girl’), which also includes existential construction (e.g. Italian c’è una bambina ‘there is a girl’). SPC constructions display the following properties: they have no phrasal subject; they have a copula; and they contain a nonverbal predicate (noun or adjective phrase) placed after the copula (Salvi Reference Salvi, Renzi, Salvi and Cardinaletti2001, II: 174–175; Cennamo Reference Cennamo, Ledgeway and Maiden2016: 979; Bentley Reference Bentley, Dufter and Stark2017).

• – Extrapositions (e.g. Italian è ovvio che ‘it is clear that’) have no phrasal subject and take a sentence as a complement to which ESC is related. The finite verb is inflected in the III sg (Manzini & Savoia Reference Manzini and Savoia2005, I: 182–183).

• – Weather verbs (e.g. Italian piove ‘it is raining’) are zero-argument verbs and have no phrasal subject. A ‘semi-argument’ can be realized and placed after the verb when referring to a non-prototypical referent (e.g. Italian piovono soldi ‘it is raining money,’ lit. money rain) (Chomsky Reference Chomsky1981; Manzini & Savoia Reference Manzini and Savoia2005, I: 182–183; Pescarini Reference Pescarini2014: 239; 2015: 70–72).

• – Epistemics (e.g. Italian sembra che i ragazzi stiano bene ‘it seems that the kids are doing well’) have no phrasal subject and take a sentence as a complement, the finite verb is inflected in the III sg. ESC is bound to the subject of the embedded clause, as is evident from the corresponding raising structures (e.g. ‘it seems that the kids are doing well’ corresponds to ‘the kids seem to be doing well’) (see, among others, Postal Reference Postal1974).

• – Impersonal si constructions (e.g. Italian si dice ‘one says’) have no phrasal subject, and the finite verb is inflected in the III sg. It is used for events with undefined, human, logically implied participants, marked by the clitic si but not explicitly realized (see, among others, Cennamo Reference Cennamo1993; D’Alessandro Reference D’Alessandro2007; Parry Reference Parry1994; Pescarini Reference Pescarini2015).

• – Impersonal deontics (e.g. Italian bisogna ‘it is necessary that’) have no phrasal subject, and the finite verb is inflected in the III sg. Impersonal deontics are zero-argument, modal verbs with a defective paradigm and take a sentence as a complement (Benincà & Poletto Reference Benincà, Poletto, Cinque, Koster, Pollock, Rizzi and Zanuttin1994; Berizzi Reference Berizzi2012).Footnote ¹⁰

As for declaratives, all baseline informants consistently reject ESCs with impersonal si and impersonal deontic constructions (8e–f). ESCs are ruled out for weather verbs (8c), as well. The baseline informants consistently use ESCs with SPC and extraposition constructions (8a–b). With epistemic constructions, ESCs are optional (8d), with the variation being both intra- and interindividual: in spontaneous production, each informant uses this construction both with and without ESCs, even within the same conversation; in acceptability judgments, all informants positively rate epistemics both with and without ESCs.

As for weather verbs, ESCs never occur in spontaneous production; in grammaticality judgments, three out of four baseline informants rule them out categorically. The only informant who positively rated ESCs in weather verb constructions is PGP. PGP is the most educated informant (holding a high school degree), worked in public institutions, and often interfaced with speakers of other Venetan varieties. Their judgment might have been influenced by the ESC systems of other varieties.

Note that in both constructions with obligatory ESC, the subject clitic attaches to copula é ‘is’. Discussing other Venetan varieties, some scholars consider this case not a real ESC but an auxiliary clitic, that is, ‘a “dummy clitic” for a position which needs to be realized once some phonological conditions (which differ across dialects) are met’ (Poletto & Tortora Reference Poletto, Tortora, Ledgeway and Maiden2016: 785; see also, Benincà Reference Benincà2007). This issue is controversial, though (cf. Poletto & Tortora Reference Poletto, Tortora, Ledgeway and Maiden2016: 785 fn. 22). Auxiliary clitics are insensitive to agreement features, which would imply that only one clitic form exists regardless of the grammatical properties of the subject. This is not the case in Opitergino, where the form of ESC is always masculine singular, as expected (8a), whereas the forms of referential subject clitics differ based on gender, both in compound forms (i.e. with an auxiliary) (9a, a’) and non-compound forms (9b, b’).Footnote ¹¹

Despite the lack of 19th-century Opitergino written texts, we were able to find chronologically comparable documentary evidence from adjoining Liventino varieties (which, as we said, belong to the same dialect group). The picture they provide is consistent with our baseline. In two texts from the nearby variety of Meduna di Livenza, ESC occurs twice in the two attested SPC constructions (2/2), once with one attested extraposition (1/1), while it does not occur with the one attested impersonal deontic [biˈzɔɲa] ‘it is necessary that’ (0/1) (Zamboni Reference Zamboni1974: 88–89).Footnote ¹² Also, data gathered between 1919 and 1928 (Jaberg & Jud Reference Jaberg and Jud1928: 14–16) in San Stino di Livenza (ASIt; maps 366, 367; data point 356) show that ESC is absent with weather verbs, both in declaratives and interrogatives.Footnote ¹³

The data in (8) occur in declaratives, in which ESCs appear to be context-sensitive. Context-sensitivity, that is, different degrees of obligatoriness of rule depending on the syntactic context, does not apply, however, to the use of ESC in interrogatives, which in conservative Opitergino is mandatory across impersonal contexts, cf. (10a–f).

3.3 Design

3.3.1 The questionnaire

We designed a questionnaire to evaluate the acceptability of the occurrence of ESCs in the impersonal constructions illustrated in Section 3.2.Footnote ¹⁴ Availing ourselves of coauthor GB’s native proficiency in Opitergino, we created ten sentences for each type of construction, and each of these sentences appeared once with an ESC and once without it. Half of the sentences were declaratives, half were interrogatives, amounting to 120 stimuli. The experimental conditions are summarized in Table 3. Given such a large number of stimuli, we chose not to add fillers. This aimed at both keeping the questionnaire fill-out time to a minimum and at avoiding loss of attention in informants.Footnote ¹⁵

Table 3 Experimental conditions (Y = with ESC; N = without ESC).

Because of the absence of corpora for Opitergino, the frequency of the stimuli could not be measured. To cope with this situation, another native speaker was asked to validate all sentences, which were rather short, composed of very familiar words, and typically used in conversational contexts. Whenever present, the ESCs never surfaced in either the initial or final sentence position. All experimental stimuli were audio-recorded by a native speaker, and an audio file was created for each sentence. All stimuli are listed in Appendix 1.

The questionnaire was administered online via the QuestionPro platform (https://www.questionpro.com/). It could be accessed through a link and filled out using PCs, smartphones, and tablets. Participants were invited to click on the play symbol, listen to each audio file, one at a time, and rate the sentence they had just heard on a 5-point Likert scale. The range of possible answers was: 1 = completely unacceptable; 2 = unacceptable; 3 = neither unacceptable nor acceptable; 4 = acceptable; 5 = perfectly acceptable. Participants were unaware of the precise objective of the study to avoid bias and automaticity in responses (they were only aware of the general objective of the study, which was to detect change in Opitergino). They were instructed to not express normative judgments but to evaluate sentences based on their perceptions, asking themselves, for instance, whether they would also use those sentences. If they would never and on no occasion use the sentence they heard because they judged it to be very bad, they were asked to assign the lowest score. If the sentence sounded very good, they should assign the highest score. If the sentence did not sound good, but not bad either, or it could have been said on some occasions, an intermediate score could be given. Once the score for a sentence was given, participants could listen to the next audio file. The fact that all stimuli were audio recordings ensured that all participants received the same stimuli under the same conditions. For the case of participants struggling with filling out the questionnaire on a digital device, help from younger persons was encouraged but limited to pressing the buttons in place of the participant. The audio files in the questionnaire were presented to each participant in a different random order. The software automatically generated a different order each time the questionnaire was accessed through the link.

Before listening to the audio files, participants were asked to anonymously answer some questions targeting their sociolinguistic profile: year of birth; gender; educational qualification; place of living; parents’ provenance; proficiency in standard Italian and in Opitergino; frequency of dialect use; and people with whom and places where the dialect is used. Relying on the Language Experience and Proficiency Questionnaire (LEAP-Q) (Marian, Blumenfeld & Kaushanskaya Reference Marian, Blumenfeld and Kaushanskaya2007), we considered these sociolinguistic measures a proxy for proficiency. In language contact situations, direct assessment of competence through language tests can be biased by many factors, while self-reported levels of competence, such as those adopted by Adamou & Shen (Reference Adamou and Shen2019), prove to be a more reliable and less biased estimate (e.g. Meakins, Green & Turpin Reference Meakins, Green and Turpin2018: 257–258).

On average, completing the questionnaire took 17 minutes.

3.3.2 Participants

One hundred and seventy-six informants were recruited through social networks, the local press, the parish, and the municipality website; they consented to participate in the survey on a voluntary basis. Informed consent was sought from each participant before taking part in the study. One hundred informants (female, f = 60; male, m = 39; other, o = 1) completed the questionnaire. As shown in Figure 1a, they were fairly well distributed by age group: younger (18–40) = 29; middle-aged (41–60) = 33; and elderly (61–92) = 38. Sixty-eight informants declared to live in the municipality of Oderzo, while 11 resided outside the province of Treviso (Figure 1b), and more than half (n = 57) had at least one parent from Oderzo (Figure 1c). Most of them reported having 13 to 16–18 years of education, which roughly corresponds to a high school diploma (n = 45) and a bachelor’s/master’s degree (n = 39), respectively (Figure 1d).

Figure 1 Demographic profile of the informants (n = 100) who completed the questionnaire.

Regarding the language profile, 69 out of 100 informants reported speaking standard Italian since before their schooling, although the proportion decreases as age increases (younger = 0.93; middle-aged = 0.64; elderly = 0.55; Figure 2a). The reverse trend is observable in the use of dialect: 61 informants reported speaking Opitergino since before their schooling (Figure 3a); however, in this case, the proportion increases as age increases (younger = 0.5; middle-aged = 0.64; elderly = 0.72; Figure 2b). While these data show the relative prevalence of dialect use across all age groups, they also confirm that other than older people, young people are more likely to have standard Italian as their L1.

Figure 2 Language use by age group (n = 100): standard Italian (2a) vs. Opitergino (2b). Expanded legend: birth; preschool, primary school, middle school, high school, after high school, passive competence.

Figure 3 Use of dialect (n = 100). In Figure 3a, the considered levels on the x-axis are: birth, preschool, primary school, middle school, high school, after high school, passive competence. NA in Figures 3b – d refers to the proportion of informants reporting passive competence in Opitergino.

Thirteen participants in the questionnaire declared passive competence of Opitergino (younger = 0.21; middle-aged = 0.06; elderly = 0.14; Figures 2b and 3a). These participants were excluded from the final analysis, which was therefore carried out on a total of 87 informants. The vast majority of informants speak a dialect (i) on a daily basis (77 out of 87; Figure 3b); (ii) mostly with family members and acquaintances (45 out of 87) but also with strangers (i.e. with everyone = 23 out of 87; Figure 3c); and (iii) in both private (i.e. home) and public (i.e. pubs, restaurants, shops, etc.) settings (32 out of 87) but also at work (i.e. everywhere = 29 out of 87; Figure 3d).

3.4 Methods for data analysis

We analyzed the data collected from the questionnaire by means of the R software (R Core Team 2020). First, we calculated the proportion of answers per point of the Likert scale in relation to the presence or absence of ESCs and the type of impersonal construction in both declaratives and interrogatives.Footnote ¹⁶ Second, following Tagliamonte & Baayen (Reference Tagliamonte and Baayen2012), we analyzed the differences in the rating of the ESCs across impersonal constructions by means of conditional inference trees and random forest, making use of the party package in R (Hothorn et al. Reference Hothorn, Buehlmann, Dudoit, Molinaro and Der Laan2006; Strobl et al. Reference Strobl, Boulesteix, Zeileis and Hothorn2007; Reference Strobl, Boulesteix, Kneib, Augustin and Zeileis2008). These non-parametric models are particularly suitable when the sample size is small, while the number of predictors is high and are robust in case of outliers. Conditional inference trees are recursive partitioning methods. The model selects ‘the predictor which helps best to distinguish between different values of the response variable’ and makes ‘a split in this variable, splitting the data in several data sets’ (Levshina Reference Levshina, Paquot and Grice2021: 612). These two steps are repeated until there are no variables that are significantly associated with the outcome. The splits are visualized as branches in a tree structure. As for a random forest, it ‘represents an ensemble method, by which many individual trees are “grown”, and their predictions are averaged’ (Levshina Reference Levshina, Paquot and Grice2021: 612). Random forests give the impact of each predictor relative to all other predictors.

We fitted two random forest models, one for declaratives and one for interrogatives, to inspect the importance of linguistic and sociolinguistic predictors in terms of their ranking. We also fitted two conditional inference tree models, again, one for declarative and one for interrogative sentences, to check whether and how the predictors interact with each other. For all models, we used the rating scores as the response variable and the following factors as predictors (independent variables):

• (α) ESC (presence of the expletive subject clitic: Y = yes, N = no);

• (β) Construction (impersonal construction type: Deo = impersonal deontic; Epi = epistemic; Extra = extraposition; Imp = impersonal si; SPC = subjectless predicative copular; Wea = weather verb);

• (γ) Age;

• (δ) Sex (f = female, m = male, o = other/prefer not to disclose);

• (ε) Education (years of education: 5, 8, 13, 16–18, >18; other);

• (ζ) P_o_L (place of living: Oderzo = municipality of Oderzo, Treviso = other municipalities in the province of Treviso, Veneto = other provinces in the region of Veneto, Italy = other regions of Italy, Other = other countries);

• (η) Parents_Origin (parents’ provenance: Oderzo = both parents from Oderzo; Oderzo(father) = only the father from Oderzo; Oderzo(mother) = only the mother from Oderzo; Other = no parents from Oderzo);

• (θ) Italian_Since (speaking Italian since: birth, preschool, primary school, middle school, high school, after high school);

• (ι) Dialect_Since (speaking a dialect since: birth, preschool, primary school, middle school, high school, after high school);

• (κ) Dialect_Freq (speaking a dialect at least once a day, week, month, year);

• (λ) Dialect_With (speaking a dialect with family/friends/strangers);

• (μ) Dialect_Where (speaking a dialect at home/at work or school/in public places).

Predictor (α) was accounted for by providing the informants with 120 sentences, of which 60 contained ESCs and 60 did not. Predictor (β) was captured by providing sentences with all types of impersonal constructions mentioned therein. Predictors (γ)–(μ) were accounted for by the sociolinguistic questions of the questionnaire preceding the audio files (cf. Section 3.3.1).

5.1 Change in declaratives

As concerns declaratives, by comparing the results of our survey with the contexts licensing the occurrence of ESCs in the baseline (cf. Section 3.2), we observe the following trends:

1. I. In the baseline, ESCs occur mandatorily in SPC and extraposition constructions, and in the 2022 survey, SPC and extraposition constructions with ESCs are strongly preferred. Accordingly, no substantial change has occurred in these contexts. This would point to (a) an overall stability. At the same time, however, stimuli without ESCs are not rated as impossible in the 2022 survey, as one would expect, based on the baseline. This amounts to an increase in the contexts in which the absence of ESCs is accepted (rule generalization) and might point to (b) an ongoing change. Also, the fact that informants assign intermediate rates to these types of constructions highlights a certain degree of uncertainty on the applicability of the rule.

2. II. In the baseline, ECSs are optionally used with epistemics. In the 2022 survey, epistemics with ESCs are rather dispreferred. This possibly points to the obliteration of optionality and amounts to (a) an ongoing change. Besides, stimuli without ESCs are rated favorably, which (b) highlights a certain degree of uncertainty on the applicability of the rule.

3. III. In the baseline, ESCs do not occur in weather verbs, impersonal si, and impersonal deontic constructions, and in the 2022 survey, weather verbs, impersonal si, and impersonal deontic constructions are preferred without ESCs than with ESCs. Therefore, no substantial change has occurred in these contexts. This would point to (a) an overall stability. However, stimuli with ESCs are not rated as impossible. This amounts to an increase in the contexts in which the presence of ESCs is accepted (rule generalization) and might point to (b) an ongoing change.

In sum, the analysis reveals a partial match of the 2022 survey with the baseline. First, no substantial rule erosion (loss) has occurred. Rather, the participants in our study did not always make clear-cut judgments about the acceptability of ESCs. For example, weather verbs, impersonal si, and impersonal deontics have not been clearly rejected when occurring with ESCs. Second, this uncertainty manifested in terms of both rule generalization (in that an ESC was accepted when occurring in contexts in which it is agrammatical in the baseline) and its omission (in that an ESC was rejected when occurring in contexts in which it is mandatory in the baseline). This change can be understood as rule weakening in terms of decreasing context-sensitivity. Third, the increasing acceptance of the absence of ESCs is likely to be an effect of contact with Italian, as a result of pattern borrowing.

These findings are in line with what Casalicchio & Frasson (Reference Casalicchio, Frasson, Chilà and Angelis2018) report on the use of subject clitics (including ESCs) with weather verbs in Paduan, Trevigiano, Venetian, and Vicentino. The authors observed an overextended use of subject clitics with weather verbs (cf. Section 2.1), but they also noted ‘a great deal of uncertainty and instability in speakers who make judgments contrary to the target: in several cases, their use of clitics seems to be optional, as they accept both contexts with clitics and without clitics’ (Casalicchio & Frasson Reference Casalicchio, Frasson, Chilà and Angelis2018: 127; our translation).

Other than Casalicchio & Frasson (Reference Casalicchio, Frasson, Chilà and Angelis2018), however, we analyzed not one but six types of impersonal constructions. While this was not sufficient to yield unambiguous results concerning the change, it still has allowed us to identify properties that might account for a higher degree of acceptability of ESCs. One such property is the fact that both constructions that scored the highest with ESCs (namely, SPC and extraposition) involve copula é ‘is’ of the auxiliary ESSERE ‘BE’. The speakers’ ratings seem to imply that the presence of a monosyllabic verbal form consisting of one vowel favors the occurrence of ESCs. At the same time, however, the ratings of the two copular constructions diverge significantly, with SPCs scoring much higher than extrapositions. This suggests that an explanation in phonological terms alone probably does not suffice.

The second property concerns processing. What really distinguishes SPC from all other construction types is the easiness with which speakers can identify a deictic, specific, and non-arbitrary subject argument, even though this is unexpressed. As a matter of fact, it has been argued that copular constructions Italian è bello ‘it is nice’ (which we subsume under SPC) have an implicit deictic subject: It could be paraphrased as qui è bello (literally ‘here is nice’) (Salvi Reference Salvi, Renzi, Salvi and Cardinaletti2001, 2: 174–175). This is clearly not the case for the impersonal si construction and impersonal deontics, for which a subject argument denoting a specific, non-arbitrary referent can hardly be retrieved (cf. Benincà & Poletto Reference Benincà, Poletto, Cinque, Koster, Pollock, Rizzi and Zanuttin1994; Reference Benincà, Poletto, van Kemenade and Vincent1997). Now, in Opitergino, ESCs are rated higher in those impersonal contexts where a deictic subject denoting a non-arbitrary referent can be recovered. From a syntactic viewpoint, this is consistent with the status of Opitergino as a pro-drop language. This would be unexpected in a non-pro-drop language, where an expletive subject pronoun (whether clitic or stressed) is mandatorily expressed and where, therefore, the possibility of tracing a semantic reference is irrelevant.

With respect to the ability to identify a deictic, specific, and non-arbitrary subject, constructions with weather verbs and with epistemics have a status that can be described as intermediate or controversial: Weather verbs are generally referred to in the literature as zero-argument verbs,Footnote ¹⁸ while in epistemics, an ESC is linked to the argument of the embedded clause.Footnote ¹⁹ At the moment, however, we are not able to provide any conclusive evaluation of the role that, more general, processing-related factors such as ease of processing might have played in the observed change.

5.2 Change in interrogatives

Let’s recall that in the Opitergino baseline (cf. Section 3.2), the presence of ESCs in interrogatives is mandatory in constructions of all sorts. The 2022 survey matches this picture as regards the ratings of stimuli with ESCs showing that no substantial rule erosion (loss) has occurred. This points to a stability of the ESC rule system in interrogatives. This stability was further confirmed by the evaluation of those stimuli lacking ESCs in our survey, for which informants provided rather unfavorable ratings. These stimuli included SPCs, extrapositions, and epistemics. However, when asked to judge stimuli lacking ESCs that included weather verbs, impersonal deontics, and (to a lesser extent) impersonal si, informants considered them fitting. Overall, this amounts to just one main difference vis-à-vis the baseline: namely, the fact that the omission of ESCs has become tolerable to some extent. These are signs of an ongoing change to the effect that, in interrogatives, the absence of ESCs with weather verbs, impersonal si, and impersonal deontics is tolerated in some measure.

5.3 Trends of change and hypotheses testing

In this section, we provide an assessment of the development of the overall ESC system in Opitergino and test the scenario of contact-induced change.

The composite picture we get by combining the results for declaratives and interrogatives allows us to observe that: (1) the Opitergino ESC system is a relatively stable rule system; (2) at the same time, it displays a quite high degree of intersubjective variation and uncertainty in the informants’ judgments (which is particularly evident in declaratives); and (3) in spite of this overall stability, a thread of change is recognizable.

The fact that a thread of change is recognizable leads us to test the hypotheses made in Section 3.1. First, we hypothesized (H1) an effect of contact with standard Italian. That change has been ongoing in Opitergino is a fact. Whether this change has been driven by contact cannot be determined with absolute certainty. However, the speakers’ increasing acceptance of the absence of ESCs is a strong clue in support of the contact hypothesis. The effect of contact between Opitergino and standard Italian is most patent in interrogatives where ESC is baseline-obligatory across all construction types.

Second, we hypothesized (H2) that contact would produce slight structural convergence towards standard Italian but would not result in the loss of ESCs. This expectation is largely backed by the observation that no substantial rule erosion has occurred. However, the increasing tolerability of the omission of ESCs, while moderate, is a symptom of an ongoing erosion.

Third, we hypothesized (H3) that change would affect ESCs in the domain of declarative clauses to a greater extent than in interrogative clauses. As a matter of fact, rule weakening has affected especially declaratives: Other than in interrogatives, where an ESC is baseline-obligatory, in declaratives, the rules’ context-sensitivity makes the situation more complex, and this has produced a change of different types (obliteration of optionality and rule generalization). This backs our hypothesis.

In addition, as regards ESCs in interrogatives, we noted that the omission of ESCs in interrogatives is rated favorably in precisely the same impersonal contexts in which the occurrence of ESCs in declaratives is rated as unfitting in our survey. These contexts are weather verbs, impersonal si, and impersonal deontic. The fact that informants gave higher scores to these constructions than to all other constructions implies that they generally accept them well, both with and without ESCs. This picture suggests that the ongoing erosion does not proceed randomly but mirrors the use of ESCs in declaratives. Given the fact that Opitergino and Italian maximally diverge relating to subject clitics and ESCs, the ways which change manifests in the recipient language (Opitergino) cannot be entirely explained by resorting to the system of the source language (Italian). Otherwise, we would only observe the loss of the ESC system, which we have not. Therefore, while contact most likely has led to change, the partial and ongoing alignment between ESCs in declaratives and ESCs in interrogatives can plausibly be ascribed to a secondary restructuring, which is internal to the Opitergino system and not due to contact.

In sum, we showed that syntactic change can manifest as decreasing context-sensitivity, leading to rule weakening. In Opitergino, this is observable both in the domain of declaratives – where change is contact-induced – and in the domain of interrogatives – where change is internally driven.