this empirical study focuses on the cross-linguistic influence of previously known languages on the acquisition of the syntax of spanish as a foreign language. the central objective is to observe if acquired languages promote the acquisition of spanish syntax as a third or fourth language. the subjects in this study are french-speaking students of spanish in a university environment at the undergraduate level in an exchange program. the instrument used was a grammatical judgment test to control certain syntactic structures of three languages: french (students？ native language), english (foreign language) and spanish (target language). the analysis focuses on data from two study groups: those for whom spanish is the l3 and those for whom spanish is the l4. results showed a major transfer from french (l1) than english (l2) in both language groups due to typological similarities and both groups performed similarly; this is partially consistent with a similar study in the acquisition of french as a foreign language (villanueva, in press).