Verb-to-INFL movement (advanced)
I. We have seen that:
(a) Auxiliaries have and be behave in many respects like modal auxiliaries and periphrastic do. Each of these elements can:
(b) There is evidence that modal auxiliaries and periphrastic do are base-generated under INFL and auxiliary have and be are base-generated under V.
II. We can capture the similarities and differences between these two groups of elements by claiming that auxiliary have and be:
(a) must move from V to INFL under certain conditions, namely when:
(NOTE: if there is more than one have or be available (in such VPs as have been working), the highest of these moves.)
(b) receive tense and agreement inflection as a result of this movement:
John is reading a book.
III. This movement also accounts for the appearance of auxiliary have and be to the left or the right of negation, depending upon whether INFL is filled by a modal auxiliary or not.