Bilinguals' Existing Languages Benefit Vocabulary Learning in a Third Language

Abstract

Learning a new language involves substantial vocabulary acquisition. Learners can accelerate this process by relying on words with native-language overlap, such as cognates. For bilingual third language learners, it is necessary to determine how their two existing languages interact during novel language learning. A scaffolding account predicts transfer from either language for individual words, whereas an accumulation account predicts cumulative transfer from both languages. To compare these accounts, twenty English-German bilingual adults were taught an artificial language containing 48 novel written words that varied orthogonally in English and German wordlikeness (neighborhood size and orthotactic probability). Wordlikeness in each language improved word production accuracy, and similarity to one language provided the same benefit as dual-language overlap. In addition, participants' memory for novel words was affected by the statistical distributions of letters in the novel language. Results indicate that bilinguals utilize both languages during third language acquisition, supporting a scaffolding learning model.

Keywords: bilingualism; neighborhood size; orthotactic probability; third language acquisition; vocabulary learning.

Figure 1

Novel word recognition accuracy. Dots and vertical lines mark observed data and standard error, lines are best fit quadratic growth curve models. A) Englishlikeness increased overall accuracy (intercept height). B) Wordlikeness collapsed across languages affected line curvature, with Wordlike items (dotted line) improving more with training and approaching an asymptote at ceiling before Unwordlike items (solid line).

Figure 2

Novel word recognition response time. Dots and vertical lines mark observed data and standard error, lines are best fit quadratic growth curve models. Both English and German wordlikness decreased overall response time across blocks (intercept height), but the two factors did not have an additive effect—double-wordlike items (E+G+, dot-dash line) were no faster than single-wordlike conditions (Englishlike only, dashed line; Germanlike only, dotted line).

Figure 3

Novel word production accuracy. Dots and vertical lines mark observed data and standard error, lines are best fit quadratic growth curve models. Both English and German wordlikness increased overall accuracy (intercept height), but the two factors did not have an additive effect. Both English like conditions (E+G−, dashed line; E+G+, dot-dash line) had higher accuracy than only-Germanlike (E−G+, dotted line).

Figure 4

Novel word production partial accuracy. Dots and vertical lines mark observed data and standard error, lines are best fit quadratic growth curve models. English and German single-wordlike conditions (dashed and dotted lines, respectively) decreased in partial accuracy over time as partially correct answers transitioned to correct responses.