This article considers the relevance of second language acquisition research for the development of pedagogical grammar. As an example it looks at the acquisition of verbal tense and aspect by intermediate-to-advanced level learners of Maltese, and more specifically the extent to which the perfett and imperfett verb forms are used by the learners when compared with L1 users of Maltese. Sixteen adult migrant learners, and 15 L1 Maltese users, took part in the study. All but one of the 16 migrant learners knew at least two other languages. Two of the participants had Arabic as their L1, and three others had learned Arabic as an L2, while the remaining learners spoke a variety of first languages. On a picture interpretation task, L1 speakers of Arabic performed very much like Maltese L1 speakers, predominantly using the perfett, perfective aspect in the past. All the other migrant learners, including those who had learned Arabic well as an L2, used the imperfett, imperfective/unrestricted habitual aspect. This evidence has important implications for the formulation of pedagogical grammar for foreign learners of Maltese. It also sheds light on the relevance of language typology in foreign language acquisition.