Developmental Issues in the Acquisition of Japanese Unaccusatives and Passives

In this paper, we re examine two competing accounts of the development of English passives in light of Japanese experimental data. It has been well-known that passives develop later than their active counterparts, but the source of the delay is still an open question. There are two major theories on the issue. One is Borer and Wexler’s (1987) A-chain Maturation Hypothesis, which claims that children’s ability to form an A-chain undergoes maturation. The other is Fox and Grodzinsky’s (1998) claim that children cannot transmit the external theta-role to the by-phrase in passives and that children comprehend actional by-phrases by default Agent assignment. In this paper, we refer to their hypothesis as the By-phrase Hypothesis. After reexamining these two theories, we claim that the source of the delay in the development of passives lies in the passive affix, rather than in the A-chain or the by-phrase. Our hypothesis is called the Passive Affix Hypothesis.