This study investigated the use of nonnative function words in the written production of learners of Italian as a third or fourth language with English, Spanish, or French as native or nonnative languages. Results show the frequent use of the French subject pronoun il (he) in learners' texts. The rate of subject insertion and omission was thus analyzed. English and Spanish first language L1 speakers with knowledge of French were found to use significantly more subject insertion than speakers without knowledge of French. This suggests that a prior exposure to a nonnative language informs learners' choices of surface structures to a significant extent and b learners with the same L1 but different prior nonnative languages develop some significant differences in their target language knowledge.