title: Investigating children’s acquisition of verb inflection in English, Swedish and Finnish: challenges for current generativist and constructivist approaches
Creators: name: Rasanen, Sanna
Publisher: name: University of Liverpool Repository
Year: 2015

description: A debate that lies in the heart of the cognitive sciences is the question of how children acquire their first language. On the one side, generativist accounts have based their explanations on innate knowledge of abstract rules, whilst, on the other, constructivist accounts explain language acquisition as a result of input-based learning. The goal of this thesis is to focus on one of the most vigorously researched areas in language acquisition, the development of inflectional verb morphology, and by doing so not only provide more insight into the acquisition of inflection in general, but also help distinguish between the two competing approaches. More specifically, the thesis will focus on three different languages – English, Swedish and Finnish – and use these languages as a testing ground for explaining how a particular aspect of language is acquired. Chapter 1 provides a general introduction to the generativist and constructivist approaches to language acquisition, as well as outlining some important linguistic terms. Chapter 2, presents with the two different linguistic phenomena under investigation in this thesis: Optional Infinitive (OI) and person/number marking errors. Chapter 3 presents Experiment 1, which reports the results of a cross-sectional elicited-production study investigating the possibility that at least some apparent OI errors reflect a process of defaulting to the form with the highest frequency in the input. Across 48 verbs, a significant negative correlation was observed between the proportion of ‘bare’ vs 3sg –s forms in a representative input corpus and the rate of 3sg –s production in simple finite contexts. This finding suggests that, in addition to other learning mechanisms that yield such errors cross-linguistically, at least some of the OI errors produced by English-speaking children reflect a process of defaulting to a high-frequency/phonologically-simple form. Chapter 4 describes Experiment 2, which further investigates the pattern of OI errors, in English and Swedish. In this study, OI errors were elicited in both simple finite and modal contexts. The results support the idea put forward in Experiment 1 that children’s (apparent) OI errors have two distinct sources: truncating compound finite structures and defaulting to the most frequent/phonologically simple form. Experiment 3 in Chapter 5 focused on examining the defaulting errors and further input effects by eliciting present tense verb forms from native Finnish-speaking children. The results provide evidence for the defaulting hypothesis, and suggest that a successful account of the development of verb inflection will need to incorporate both rote-storage and retrieval of individual inflected forms as well as phonological analogy across them. Finally, Chapter 6 concludes the thesis by summarizing the findings of Experiments 1-3, and discussing the main implications of the results for the generativist and constructivist accounts of acquisition of verb morphology, as well as suggesting some possible future research directions.