The "wanna" facts are a classic Poverty of Stimulus (PoS) problem: "Wanna" is grammatical in certain contexts ("Who do you want PRO to play with?") but not others ("Who do you want who[strikethrough] to play with you?"). On a standard analysis, "contraction" to "wanna" is blocked by some…

Two recent proposals link the use of nonagreeing "don't" to the Root Infinitive (RI) Stage. Guasti & Rizzi (2002) argue for a misset parameter involving how agreement is spelled out. Schütze (2010) proposes that Infl is underspecified in child language and that "do" surfaces to support the contracted clitic/affix…

The 1990s witnessed a major expansion in research on children's morphosyntactic development, due largely to the availability of computer-searchable corpora of spontaneous speech in the CHILDES database. This led to a rapid emergence of parallel findings in different languages, with much attention devoted to the widely attested difficulties in…