This paper reports on an experimental study of the expression of genericity in the acquisition of English by native speakers of Spanish and Brazilian Portuguese, and in the acquisition of Brazilian Portuguese by native speakers of English and Spanish. English, Spanish and Brazilian Portuguese exhibita threeway distinction in terms of which NP types are allowed with generic and kind interpretations. This difference leads to specific, testable predictions for the effects of cross-linguistic influence on the expression of genericity in second language acquisition. These predictions are tested in a small-scale study, by means of a written, context-based Acceptability Judgment Task. The results show that transfer from the learners' native language has a limited effect, and is overridden by considerations of register and/or input frequency. The findings pose interesting questions for further research.