caa a22 4500 386359563 CHVBK 20180307111911.0 cr unu---uuuuu 161130e198910 xx s 000 0 eng 10.1017/S0305000900010692 doi S0305000900010692 pii (NATIONALLICENCE)cambridge-10.1017/S0305000900010692 The transition from optional to required subjects [Elektronische Daten] We propose (contra Hyams, 1986) that the optional subject phenomenon in early child language arises because children have not yet acquired the morphological elements (primarily modals and tense) necessary to distinguish Subject-Taking (ST) verbs (e.g. finite verbs) from their non-Subject-Taking (NST) counterparts (e.g. infinitives). Unaware of this distinction, children are able only to observe that verbs sometimes occur with subjects and sometimes without. We show that our proposal makes a number of developmental predictions which we then test with the help of longitudinal data from three children. We conclude that: (i) There is no systematic morphological distinction between ST and NST verbs during the optional subject stage (OSS). (2) The emergence of the distinction between ST and NST verbs is gradual rather than sudden. (3) There is variation from child to child in terms of which morphologically-defined subclass of verbs is first recognized as subject-taking. (4) There is no link between the emergence of modals or contracted copulas and the end of the OSS. Copyright © Cambridge University Press 1989 O'Grady William University of Calgary Peters Ann M. University of Hawaii Masterson Deborah University of Hawaii Journal of Child Language Cambridge University Press 16/3(1989-10), 513-529 0305-0009 16:3<513 1989 16 JCL https://doi.org/10.1017/S0305000900010692 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0305000900010692 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- O'Grady William University of Calgary NATIONALLICENCE 700 1- Peters Ann M. University of Hawaii NATIONALLICENCE 700 1- Masterson Deborah University of Hawaii NATIONALLICENCE 773 0- Journal of Child Language Cambridge University Press 16/3(1989-10), 513-529 0305-0009 16:3<513 1989 16 JCL CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge