The discussion begins with a presentation of two conflicting hypotheses about FL/L2 reading: the Linguistic Threshold Hypothesis (Clarke 1980; Yorio 1971) and the Linguistic Interdependence Hypothesis (Cummins 1979a, 1986, 1991). The short circuit hypothesis, recently referred to as the Linguistic Threshold Hypothesis (LTH), claims that in order to read in FL/L2, a learner must reach a certain level of FL/L2 linguistic ability. The Common Underlying Proficiency (CUP) Hypothesis, recently referred to as the Linguistic Interdependence Hypothesis, states that FL/L2 reading performance largely depends on L1 reading abilities. Let us focus on the two hypotheses and the research evidence supporting their presumptions.

The Linguistic Threshold Hypothesis

FL/L2 proficiency plays a considerable role in FL/L2 reading. The Linguistic Threshold Hypothesis claims that in order to read in FL/L2, the learner must reach a certain level of target language linguistic ability. The results of reading studies, e.g., Devine (1993) and Kusiak (2000), indicate that there is an interdependence between FL/L2 language proficiency and FL/L2 reading abilities.

The Linguistic Threshold Hypothesis also concerns the question as to whether limited proficiency in FL/L2 restricts readers in using very specific types of textual information, such as the discourse constraints of a text. Cziko's (1978) studies indicated that the reading performance of advanced English proficiency French students resembled that of native English speakers; they were more sensitive to syntactic, semantic and discourse constraints in a text and applied more nontextual information.