I have proposed four mechanisms that acquire lexical entries: L1, L2, L4, and L5 (recall that L3 acquires the general paradigms used by L4 and L5). These procedures can be organized into a taxonomy that will become useful when we examine the evidence concerning lexical development. The taxonomy, displayed in figure 17 [immagine], classifies the procedures in terms of whether they are productive or unproductive (i.e., whether they can create subcategorization frames that are not exemplified in the input), whether they are lexically or thematically based (i.e., whether a particular lexical entry or a particular set of thematic roles serves as input to the procedure) [...].
- Pinker (2004), a pag.253