Tariana has two valency reducing operations – passive (§13.1) and reflexive-reciprocal (§13.2), and three valency increasing causativising mechanisms (considered in §13.3). There is also an argument-adding mechanism distinct from both causatives and applicatives (see §13.4). Another mechanism does not affect the transitivity value of a verb, but instead rearranges the arguments (§13.5). §13.6 contains a summary of valency changing and argument rearranging mechanisms, showing that their application provides additional evidence as to what grammatical relations must be distinguished in this language.

Passive

Passive is marked with prefix ka- (also used in participles – see Chapter 20) and suffix -kana. It can be followed by an auxiliary verb -a ‘go, do, give’ which takes the subject prefix. When a passive form is negated, ka- is replaced by ma- ‘negative’ and the negative suffix -kade is added after -kana (also see §17.2).

Passive can be derived from any verb except for those of the Sio type. Passives derived from (A) transitive and ditransitive, (B) prefixed active intransitive (Sa) and (C) prefixless verbs (So) have different semantic effect. Passives can be nominalised; they then show some functional and semantic overlap with passive participles; see (D). The syntactic functions and the pragmatic effect of the passive is discussed in (E).