The Causative-Inchoative Alternation and Age-of-Acquisition Effects on Multi-predicate Constructions in Turkish Sign Language

ABSTRACT We discuss the causative-inchoative alternation in Turkish Sign Language (Türk İşaret Dili – TİD), and the age of acquisition effects on multi-predicate, complex constructions that are observed in both causative and inchoative events. We present a picture-description task performed by 24 adult signers, half of which were exposed to TİD from birth (native adult signers) and the other half after the age of 4 (late adult signers). The results show that (i) the causative-inchoative alternation in TİD is attested both as labile alternation and classifier alternation; (ii) there is no significant age of acquisition effects on the choice of alternation types; (iii) both causative and inchoative events have complex event structures that can be overtly expressed through multi-predicate, complex constructions; and (iv) late signers are less likely to produce multi-predicate, complex constructions than native signers. These results support the significance of deaf individuals’ early exposure to a sign language.