A study of the interlanguage of bilinguals and multilinguals compared the oral French proficiency of 20 native Swedish-speaking and 20 Finnish-speaking university students as evidenced in error patterns in oral tests. With the exception of phonological and phonetic errors in pronunciation, errors were classified by word class (article, noun, adjective, pronoun, numeral, verb, adverb, preposition, conjunction), grammatical category (gender, number, determination, person, mood, tense), linguistic unit (morpheme, word, syntagme, phrase, vowel, consonant, group, syllable), nature of the error (substitution, omission, superfluous element, order), and linguistic level (morphological, syntactical, lexical, phonological, phonetic, suprasegmental). The error patterns suggest some specific points of divergence between the two student groups. The error patterns also suggest that the relative number of errors caused by native language interference in Finnish versus Swedish interlanguage is reduced because of the plurilingualism of many of the students; there are sources of error other than transfer; there are noticeable differences between students, related to personality; and the better marks obtained by Swedish-speaking students cannot be explained by the smaller number of errors they made. (MSE)