REALISATIONS OF THE ELEMENTS: LEXICAL VERBS AND AUXILIARIES
The elements of the VG are realized by the following classes and forms of verbs:
• lexical verbs: wait, come, rain, bring, etc.
• primary verbs: be: am, is, are, was, were, being, been; have: has, had, having; do: does, did
• modal auxiliaries: shall, should, will, would, can, could, may, might, must, ought to
• semi-modals: need, dare, used to (modals in certain uses)
• lexical auxiliaries:
(1) be able to, be about to, be apt to, be bound to, be due to, be going to, be liable to, be likely to, be certain to, be sure to, be to, be unlikely to, be supposed to
(2) have to, have got to
(3) had better, would rather, would sooner
The primary and modal verbs are limited in number, as this list shows, and form closed sets. Lexical verbs, the v or main element, constitute an open set; new ones can be coined and added to the lexicon at any time.
The primary verbs carry grammatical meaning (tense, aspect, person, number), the modal auxiliaries express modal meanings (obligation, possibility, probability, necessity) rather than lexical or grammatical meaning. On the other hand, the lexical element of the verbal group expresses both lexical meaning and grammatical meaning.
The primary verbs be, have, do can function both as auxiliary and as lexical elements of the VG (with the exception of doing and done, which function only as lexical elements). The syntactic function determines the type of meaning expressed, whether grammatical or lexical, as shown here.
In addition to its function as a main verb, be therefore has three auxiliary functions: as an aspect auxiliary in the progressive: is taking; as a passive auxiliary: is taken; and as the basis of the lexical auxiliaries that take be.
