Lexicalization patterns(LPs) differ from one language to another. This study investigates the influence of L1 LPs on the processing of L2 words in sentential contexts by Persian learners of English. The focus was on cases where two different senses of a polysemous word in Persian are realized by two independent words in English. The participants were presented with two types of anomalous sentences: test sentences in which one of the two English words was used in a context where the other word was appropriate and control sentences in which the same word was used in a context where neither of the two words was appropriate. The participants were asked to judge, as quickly and accurately as possible, whether the final word could complete the sentence meaningfully or whether the final word was semantically unacceptable. The participants'' reaction times for correct No responses and their error rates were recorded. A main effect of sentence type and an interaction between sentence type and proficiency level were obtained in the analysis of both RTs and errors. The findings of this study have implications for L2 vocabulary teaching and learning.