A basic problem that must be dealt with in order to build an intelligent tutoring system (ITS) in the domain of foreign language teaching is that of establishing what kind of grammatical knowledge has to be included in the domain expert module. Two basic options are possible: (i) to use a naive or pedagogical grammar, comprising knowledge derived from textbooks and school grammars or (ii) to use one of the formal grammars developed by theoretical and computational linguists.
