The study of how learners acquire a second language (SLA) has helped to shape thinking about how to teach the grammar of a second language. There remain, however, a number of controversial issues. This paper considers eight key questions relating to grammar pedagogy in the light of findings from SLA. As such, this article complements Celce-Murcia's (1991) article on grammar teaching in the 25th anniversary issue of TESOL Quarterly, which considered the role of grammar in a communicative curriculum and drew predominantly on a linguistic theory of grammar. These eight questions address whether grammar should be taught and if so what grammar, when, and how. Although SLA does not afford definitive solutions to these questions, it serves the valuable purpose of problematising this aspect of language pedagogy. This article concludes with a statement of my own beliefs about grammar teaching, grounded in my own understanding of SLA.