6.1 The structure of IP
However, the traditional assumption is challenged by the analysis in (4), where it is claimed that clauses most definitely do have heads. There is much evidence to support this. Firstly consider the relationship between the inflection and the clause. The inflections come in two basic types: finite and non-finite. The finite inflections consist of the modal auxiliaries and tense morphemes. The infinitival marker to is non-finite, but we also get clauses, traditionally called participles, in which the inflection on the highest verbal element is either ing or en (or one of its irregular versions):