Grammar exercises for language learning fall into two distinct classes: those that are based on ''real life sentences'' extracted from existing documents or from the web; and those that seek to facilitate language acquisition by presenting the learner with exercises whose syntax is as simple as possible and whose vocabulary is restricted to that contained in the textbook being used. In this paper, we introduce a framework (called gramex) which permits generating the second type of grammar exercises. Using generation techniques, we show that a grammar can be used to semi-automatically generate grammar exercises which target a specific learning goal; are made of short, simple sentences; and whose vocabulary is restricted to that used in a given textbook.