Expansion of the VP structure: coexistence of VP and IP structures
In file 3, two other modal verbs appear, wollen (‘want’) and mussen (‘have to’). The correct placement of adverbs (cf. (542)) or negators (cf. (543)) inside the verb bracket provide support for the availability of the IP level at this stage. Sentential patterns continue to include SVX, V3 and verbless constructions.
In contrast to his early use of modal verbs, Fuad produces the first constructions with the auxiliary verbs haben (‘to have’) (cf. (544)) and sein (‘to be’) (cf. (545)) only in file 4. Although participle formation is rule-based at this stage, verb- specific characteristics remain to be attained. Further, although the target-like sequence with a separable verb in (cf. (546)) might indicate that verb raising is operative in this file, the preverbal placement of the adverb in example (547) shows that the process is not applied across the board. At closer inspection, the data reveal a discrepancy regarding non-thematic and thematic verbs, whereby the former comprise auxiliary, modal or copula verbs, and the latter main verbs. Whereas non-thematic verbs appear in I, thematic verbs appear to remain in the VP. The examples produced in file 5 reveal the continuity of this discrepancy until the end of the recording time covered in this study (compare example (548) with a non-thematic verb and example (549) with a lexical verb preceded by the negator nicht).