The verb string: tense, aspect and mood
As we saw in Chapter 18, Cognitive Grammar analyses the verb string in terms of a grounding predication (either a tense morpheme or a modal verb) and a clausal head, which can include a perfect construction, a progressive construction and a passive construction, as well as the content verb. This partition of the verb string is illustrated by example (9).
As Langacker (1991: 195) acknowledges, this partition of the verb string is also reflected in the transformational model, where the modal or finite auxiliary occupies the head of the TP or tense phrase (in other words, heads the sentence as a whole), and the remainder of the verbs occupy positions within an extended verb phrase. This is represented in Figure 22.9.
According to the transformational model, the fact that the finite verb pre cedes negation means that negation heads its own functional phrase in between TP and VP. This pattern is illustrated by the examples in (10).
Example (10a) shows that when the clause lacks a modal verb, the next verb in the string (here, the perfect auxiliary have) becomes finite. According to the transformational model, this means that the relevant verb raises to the T position, an analysis that receives some support from the relative ordering of the finite verb and the negation element. Example (10b) makes the same point, but in this case it is the progressive auxiliary be that raises. Example (10c) shows that the lexical verb cannot raise; in this case, the ‘dummy auxiliary’ do is inserted into the clause in order to provide morphological ‘support’ for tense, which is a bound morpheme. This means that in a sentence like Lily ate shell fish, the tense morpheme must ‘lower’ to attach to the lexical verb. The same pattern is evident in the behaviour of lexical and content verbs with respect to (negated) subject-auxiliary inversion, as illustrated by example (11). Observe that when negation is cliticised to the verb (-n’t), it raises with the verb to a position preceding the subject. When the negation element remains a free morpheme (not), it does not raise with the auxiliary verb.
The Cognitive Grammar account and the transformational account are similar in that both accord a special status to the first element in the verb string, and this special status relates to its tense properties. Both models provide an account based on the idea that that it is finiteness that licenses the clause to stand alone as an independent grammatical unit. However, the Cognitive Grammar account analyses tense/mood properties in terms of what they contribute to the semantics of the clause as a grounding predication, while the transformational account emphasises the grammatical behaviour of the finite verb. Secondly, the Cognitive Grammar account analyses the string of verbs containing the lexical or content verb as the clausal head, while the transformational account views tense features (roughly, the equivalent of Langacker’s grounding predication) as the clausal head. It is worth emphasising that only the transformational model accords this status to tense features. Other formal models, including HPSG, view the lexical verb as the head of the clause.
