The purpose of the current study is to examine language influence in sequential bilinguals. Specifically, this study evaluates whether performance in a first language predicts success in the acquisition of a second language nine months after exposure to the second language begins. Forty-nine Spanish-speaking children attending English-only pre-kindergarten classrooms participated in the study. Children were assessed in Spanish at the beginning of the school year using the Spanish version of the Bilingual English Spanish Assessment (BESA), MLU in words, and a lexical diversity measure, D, obtained from a language sample. Nine months later, children were assessed in English using the English-BESA. Analyses indicated significant correlations between semantic and grammatical measures across languages. Stepwise regression analyses found that grammatical and semantic measures in the first language robustly predicted grammatical and semantic measures in the second language. We propose that native language skills predict the success in second language acquisition, not because of linguistic transfer, but by virtue of individual differences in language learning abilities present in typical populations.