In a study with seventh- and eighth-graders, Spanish-English bilinguals (n=41) and English monolinguals (n=48) used brief English contexts to choose among possible meanings for unfamiliar words. Two types of errors were compared: transfer errors, which were answers consistent with Spanish but not English syntax, and non-transfer errors, which were inconsistent with the syntax of both languages. Non-transfer errors were found to be negatively correlated with reading proficiency in both Spanish and English. Transfer errors were positively correlated with reading proficiency in Spanish and were unrelated to English reading proficiency. First-language syntactic knowledge was thus found to influence guesses about the meanings of unfamiliar words in a second-language context. The effects was found among bilinguals who had experienced a variety of amounts and types of exposure to English. (Author/MSE)