Two groups of Mandarin–English bilingual children (3–5-year-olds, 6–8-year-olds) participated in a picture identification task and a picture naming task in both languages. Results revealed age-related growth in English, but not Mandarin vocabulary. Composite vocabulary was larger than either single-language vocabulary in the younger children but was similar to English vocabulary in the older children. Furthermore, children showed a larger receptive–expressive modality difference in their weaker language (Mandarin) than in their stronger language (English). These patterns indicate rapid growth in English vocabulary along with early stabilization of Mandarin vocabulary despite considerable Mandarin input in the home setting.

Second language acquisition studies can contribute to the body of research on the influence of language on thought by examining cognitive change as a result of second language learning. We conducted a longitudinal study that examined how the acquisition of Spanish grammatical gender influences categorization in native English-speaking adults. We asked whether learning the grammatical gender of Spanish affects adult native English speakers' attribution of gender to inanimate objects. College students enrolled in beginning Spanish participated in two tasks repeatedly (four times) throughout one academic year. One task examined their acquisition of grammatical gender. The other examined their categorization of inanimate objects. We began to observe changes in participants' grammatical gender acquisition and in categorization after ten weeks of Spanish instruction. Results indicate that learning a second language as an adult can change the way one categorizes objects. However, the effect of Spanish grammatical gender was more limited in Spanish learners than in native Spanish speakers; it was not observed for all kinds of objects nor did it increase with learners' proficiency, suggesting that adults learning Spanish reach a plateau beyond which changes in categorization do not occur.

Young English-speaking monolingual and bilingual adults were examined for English proficiency, language use history, and performance on a flanker task. The bilinguals, who were about twenty years old, were divided into two groups (early bilinguals and late bilinguals) according to whether they became actively bilingual before or after the age of ten years. Early bilinguals and monolinguals demonstrated similar levels of English proficiency, and both groups were more proficient in English than late bilinguals. In contrast, early bilinguals produced the smallest response time cost for incongruent trials (flanker effect) with no difference between monolinguals and late bilinguals. Moreover, across the whole sample of bilinguals, onset age of active bilingualism was negatively correlated with English proficiency and positively correlated with the flanker effect. These results suggest a gradient in which more experience in being actively bilingual is associated with greater advantages in cognitive control and higher language proficiency.

Malay (Rumi) is alphabetic and has a transparent, agglutinative system of affixation. We manipulated language-specific junctural phonetics in Malay and English to investigate whether morphophonemic L1-knowledge influences L2-processing. A morpheme decision task, “Does this <nonword> sound like a mono- or bi-morphemic English word?”, was developed by crossing English Transitional Probability (high vs. low) with Malay Transitional Possibility (possible vs. impossible). The data for Malay-L1/English-L2 adults (N = 21) provide clear and reliable empirical evidence of L1-to-L2 morphophonemic transfer: Participants were more accurate at identifying transitional boundaries in English when they are also possible in Malay. Pedagogical implications are discussed.

Can transfer occur in child bilingual syntax when surface overlap does not involve the syntax-pragmatics interface? Twenty-three Spanish/English bilingual children participated in an elicited imitation study of clitic placement in Spanish restructuring contexts, where variable word order is not associated with pragmatic or semantic factors. Bilingual children performed poorly with preverbal clitics, the order that does not overlap with English. Distinct bilingual patterns emerged: backward repositioning, omissions (for simultaneous bilinguals) and a reduction in forward repositioning bias. We conclude that transfer should be defined in lexical terms as the result of priming effects leading to shifts in lexical items.

An increasing number of schools offer bilingual programs, where lessons are taught in more than one language. Several theories state that bilinguals have greater metalinguistic awareness than monolinguals. We investigated whether this greater metalinguistic awareness is also related to an increased ability to understand an unknown language. To measure metalinguistic awareness and the ability to understand text written in an unknown language, we designed the Indonesian Language Test (ILT). The ILT consists of items regarding a story in Indonesian. Dutch high school students from monolingual and bilingual classes were administered the ILT, a Dutch Language Test, an English Language Test, and a general intelligence test. The ILT showed promising psychometric properties. Bilingual students scored significantly higher on the ILT than monolingual students. Multi-group confirmatory factor analyses showed (i) that ILT measures the ability to understand an unknown language, and (ii) that bilingual students score significantly higher than monolingual students on this ability. Both observations support the notion that bilingual education increases metalinguistic awareness and therefore the ability to understand an unknown language.

This research examines the processes which native Spanish-speaking learners of English and English-only students engage in when inferring meaning for unknown English words that have Spanish cognates. Conducted within the context of a large-scale vocabulary intervention that taught word inferencing strategies, including a cognate strategy, this qualitative study describes cognate strategy use among a small sample of participants. The data suggest that explicit instruction, students' metalinguistic and metacognitive skills, and the structural characteristics of cognate pairs are associated with cognate recognition.