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…

Bilingual children with a limited command of the second language (L2) often yield unsatisfactory results in L2-based non-word repetition tasks (NWRT) for the assessment of working memory. In this study, monolinguals (MO) and bilinguals (BI) of preschool age acquiring German were compared in regard to their performance on German-based NWRT to…

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)…

High rates of error and variability in early word production may signal speech sound disorder. However, there is little consensus regarding the degree of error and variability that may be expected in the typical range. Relatedly, while variables including child age, word frequency and word phonological neighbourhood density are associated with…

This study explored the patterns and predictors of code-switching (CS) in Singapore preschoolers by analyzing the data elicited from an existing early childhood corpus. Altogether 943 cases of CS produced by 111 children aged 2;6, 3;6, 4;6, 5;6, respectively, were analyzed. The results indicated that: (1) 'insertion', 'intersentential', and…

Input variability is key in many aspects of linguistic learning, yet variability increases input complexity, which may cause difficulty in some learning contexts. The current work investigates this trade-off by comparing speaker variability effects on L2 vocabulary learning in different age groups. Existing literature suggests that speaker…

This longitudinal study examined the development of narrative micro- and macrostructure in Japanese-English bilingual returnee children. Returnees are children of immigrant families who move to a foreign country, spending a significant portion of their formative developmental years in the foreign majority language context before returning to their…

Narrative production draws upon linguistic, cognitive and pragmatic skills, and is subject to substantial individual differences. This study aimed to characterise the development of narrative production in late childhood and to assess whether children's cumulative experience of reading fiction is associated with individual differences in narrative…

This study investigated the predictions of two approaches to second language acquisition. According to the usage-based approach, learner knowledge results from the strengths and weaknesses of input-driven statistical learning. According to the learner-varieties approach, pragmatic communication principles and language-internal constraints play…

This study examined the optimal learning schedule for second language vocabulary within an authentic classroom setting in Hong Kong. Following a pretest, treatment, delayed posttest design, fifty-two primary school students (Cantonese first language) studied 20 English adjectives over two learning episodes under spaced-short (1-day interval) or…

Language learning requires linguistic input, but several studies have found that knowledge of second language (L2) rules does not seem to improve with more language exposure (e.g., Johnson & Newport, 1989). One reason for this is that previous studies did not factor out variation due to the different rules tested. To examine this issue, we…

This study investigates the interpretation of disjunction words (English or) in negative sentences by Turkish- and German-speaking children. Both children and adults were asked to judge Turkish/German sentences corresponding to the English sentence "This animal did not eat the carrot or the pepper." Children acquiring both languages…

We report a longitudinal comprehension study of (long) passive constructions in two native-Spanish child groups differing by age of initial exposure to L2 English (young group: 3;0-4;0; older group: 6;0-7;0), where amount of input, L2 exposure environment, and socioeconomic status are controlled. Data from a forced-choice task show that both…

This quasi-experimental quantitative study examined the effects of different multimedia learning environments on the learning outcomes of second language learners. The study was designed to specifically assess Mayer's redundancy principle by investigating whether there was a difference in performance outcomes of second language learners…