Diachronic change: early versus late acquisition

There is a long linguistic tradition in which language change is explained in terms of first language acquisition. In this tradition, children are considered to be the agents of language change, or at least the agents of changes in the underlying grammar. Since the early 1980s, this has been formulated in the (generative) terminology in terms of parameters set by children: whereas an older generation acquires one particular setting of a parameter (during childhood), a next generation of L1 children may set a parameter differently, based on the input of their parents, and this may lead to a different output. For obvious reasons this argumentation had to be built on theoretical rather than empirical work on language acquisition. There are no children acquiring Old English or Middle Dutch, and, in fact, the field of acquisition research was until recently much less developed and very often not focused on the type of facts that happened to play a role in discussions of language change

Effects of age on the acquisition of agreement inflection

Grammaticality judgement tasks show that second language learners who started during childhood are significantly more accurate on judging inflection than learners who started after puberty [Johnson, J., & Newport, E. (1989). Cognitive Psychology, 21, 60-99; Johnson, J., & Newport, E. (1991). Cognition, 39, 215-258; McDonald, J. (2000). Applied Psycholinguistics, 21, 395-423. Production data confirmthat inflection is a bottleneck in adult language acquisition, and that they differ from child learners in this respect [Lardiere, D. (1998). Second Language Research, 14, 359-375; Prévost, P. (2003). Studies in Second Language Acquisition, 25, 65-97; Pre vost, P., & White, L. (2000). Second Language Research, 16(2), 103-133]. Although the observations suggest that the acquisition of inflection is influenced by age, there is no study that focuses on this particular issue nor is there an articulated explanation available for the observed age-related difference. In this contribution, we compare child L2 learners of Dutch to child L1 and adult L2 learners of Dutch in order to investigate effects of age on the acquisition of verbal and adjectival inflection. We hypothesize that adult agreement paradigms differ from child agreement paradigms, the reason being that adult learners cannot rely on syntactic cues, whereas children make reliable use of syntax in building paradigms. By effect, adult learners end up with non-targetlike small paradigms that contain underspecified suffixes. We focus on the types of errors in the three learner groups (child L1, child L2 and adult L2). Our empirical basis consists of results obtained in a series of production experiments