We have examined elicited production data of two groups of multiple language learners: HungarianL1/GermanL2/EnglishL3 and HungarianL1/SpanishL2/EnglishL3. Results show nuanced differences in acquisition patterns, which we attribute to the minimal difference in learners’ background languages. It also implies that learners’ syntactic fluency can be enhanced in principled and selective ways.