This dissertation investigated how four factors -- the degree of L2 experience, L1 sound structure, age difference in L1 language development and age of L2 exposure -- affect the perceptual cue weighting of duration and spectral differences for English tense-lax vowel contrasts. Four major hypotheses were tested: desensitization hypothesis (DH)…

The age at which people acquire a word influences word recognition, known as the age of acquisition (AoA) effect. In the first language (L1), AoA effects are widely found in various languages and experimental tasks. Arbitrary Mapping Hypothesis proposes that AoA effects reflect the loss of network plasticity during the learning of mappings between…

The Less-Is-More hypothesis was proposed to explain age-of-acquisition effects in first language (L1) and second language (L2) learning. We scrutinize different renditions of the hypothesis by examining how learning outcomes are affected by (a) limited cognitive capacity, (b) reduced interference resulting from less prior knowledge, and (c)…

Pierce "et al." (2017) have proposed that variations in the timing, quality and quantity of language input during the earliest stages of development are related to variations in the development of phonological working memory and, in turn, to later language learning outcomes. To examine this hypothesis, three groups of children who are…

A recurring question in the literature of heritage language acquisition, and more generally of bilingual acquisition, is whether all linguistic domains are sensitive to input reduction and to cross-linguistic influence and to what extent. According to the Interface Hypothesis, morphosyntactic phenomena regulated by discourse-pragmatic conditions…

This dissertation focuses on when and how children learn about the meanings of the propositional attitude" verbs know" and "think". "Know" and "think" both express belief. But they differ in their veridicality: "think" is non-veridical and can report a false belief; but "know" can only…

A well-known challenge for language learners is that the input is typically produced by a variety of speakers, each with distinct vocal characteristics (Liberman, Harris, Hoffman, & Griffith, 1957). Accordingly, many studies have indicated that talker variability leads to processing costs for learners across the lifespan (Jusczyk & Pisoni,…

This study employs the Specificity Principle to examine the relative impacts of external (input quantity at home and at school, number of books and reading frequency at home, teachers' degree and experience, language usage, socioeconomic status) and internal factors (children's working memory, nonverbal intelligence, learning-related…

Structural priming is a useful laboratory-based technique for investigating how children respond to temporary changes in the distribution of structures in their input. In the current study we investigated whether increasing the number of object relative clauses (RCs) in German-speaking children's input changes their processing preferences for…

The dissertation study aims to contribute mainly to the field of loanword phonology in general and particularly to Indonesian and its phonology that are rarely studied to date. The study investigates what consonantal and syllabic repair strategies are employed by Indonesian in adapting Arabic and Dutch loanwords, whether these adaptation…

According to the critical period hypothesis, the earlier the acquisition of a second language starts, the better. Owing to the plasticity of the brain, up until a certain age a second language can be acquired successfully according to this view. Early second language learners are commonly said to have an advantage over later ones especially in…

The effects of age on second language acquisition constitute one of the most frequently researched and debated topics in the field of Second Language Acquisition. Two different orientations may be distinguished in age-related research: one which aims to elucidate the existence and characteristics of maturational constraints on the human capacity…

Explored effects of interactional feedback on children's second language (L2) development in a prettest/posttest design. Child learners carried out communicative tasks that provided contexts for targeted forms and interactional feedback to occur. An experimental group received interactional feedback in response to non-targetlike production of…