The clausal head
According to Langacker (1991), the traditional partition of the verb string into auxiliary verb(s) on the one hand and lexical verb on the other does not correctly reflect the semantic division of labour within the verb string. While it is clear that auxiliary verbs have a number of properties that distinguish them from lexical or content verbs, Langacker proposes that the verb string should be partitioned into grounding predication and clausal head. The grounding predication is the part of the verb string that is responsible for finiteness. In English, this is either the first element in the verb string (a modal verb) or is attached to the first element in the verb string (a tense morpheme). The remain der of the verb string, including any other auxiliary verb(s) together with the content verb, makes up the clausal head. This is illustrated by example (1).
Recall that if the sentence contains a modal, as in example (1), none of the other verbs in the string are finite (marked for tense). In the absence of the modal, the first verb in the string is finite. In example (2a), the perfect auxiliary have is finite (present tense) while in example (2b) the progressive auxiliary be is finite (past tense). If the lexical or content verb is the only verb in the string, this verb is finite; in (2c) the lexical verb sing occurs in its past tense form.
As the examples in (2) demonstrate, it is not always possible to separate a tense morpheme from the verb. This is because some English verb forms mark grammatical distinctions by vowel changes (ablaut). Cases where the tense morpheme can be separated from the verb are the third person singular present tense form of most verbs (walk-s), and the past tense form of some verbs (walk ed). In this section, we concentrate on Langacker’s account of the clausal head. We return to the grounding predication in the next section.
Within the clausal head, the lexical or content verb provides the content meaning. The leftmost verb functions as the profile determinant for the entire clause; Langacker calls this verb the grounded verb, because it is under the direct control of the grounding predication. For example, as we saw in (2), the leftmost verb, lexical or auxiliary, is marked for tense in the absence of a modal verb. Langacker’s (1991: 198) representation of the organisation of the complex clausal head in English is represented in (3a).
In the representation in (3a), have is the perfect auxiliary and PERF represents the ‘past’ or perfect participle morphology (for example, -ed or -en). The sub scripts represent the different senses of the perfect participle in perfect constructions (PERF4) and passive constructions (PERF3), which are elaborated below. Equally, the subscripts on the be auxiliaries indicate the different senses of this verb in progressive constructions (be1) and passive constructions (be2). The morpheme -ing represents the ‘present’ or progressive participle. Finally, V represents the content verb. Observe that the modal is not included in this representation of the verbal complex. Recall that this is because, if the clause contains a modal verb, it functions as the grounding predication. The example in (3b) illustrates a verb string that contains all the elements in this complex clausal head (bracketed). The verb have is the perfect auxiliary; the verb been is the perfect participle (PERF4) form of the progressive auxiliary (be1). The verb being is the progressive participle (-ing) form of the passive auxiliary (be2). Finally, the verb stalked is the ‘past’ participle (PERF3) form of the lexical verb (V), which is required by the passive auxiliary. As we explain below (section 18.2.1), this verb form, which we call the ‘passive participle’, is semantically related to the perfect participle in Langacker’s analysis, hence its ‘PERF’ label.
As this example shows, the elements that make up the complex clausal head (3a) do not occur separately in the verb string, but are ‘glued together’ by morphology. Of course, not all clausal heads are as complex as the example in (3). Some clauses might just contain a single finite lexical verb. We look at each of the component parts of this complex clausal head in more detail below.
As Langacker (1991: 199) observes, a number of striking patterns emerge from the representation in (3a). To begin with, moving from right to left, the elements alternate between phonologically autonomous and phonologically dependent units. For example, the content verb is phonologically autonomous while the ‘past’ participle morphology is a dependent (affixal) form. The passive auxiliary is phonologically autonomous while the progressive participle morphology -ing is a dependent (affixal) form, and so on. Secondly, recall from Chapter 16 that participles, as non-finite verb forms, are classified as ATEMPORAL RELATIONS. This means that the phonologically dependent forms in (3a) (participial morphemes) have ATEMPORAL RELATIONS at their semantic poles. In contrast, Langacker argues that the phonologically autonomous forms (the auxiliary verbs have and be, together with the content verb) have TEMPORAL RELATIONS (PROCESSES) at their semantic poles. In other words, the Cognitive Grammar analysis of the primary auxiliaries have and be relates these semantically to their non-auxiliary (lexical) counterparts. Thirdly, at each ‘level’ in the increasingly complex clausal head construction, the leftmost element functions as the profile determinant, so that the constructions within this representation also alternate between PROCESS and ATEMPORAL RELATION, which in turn has consequences for how the complex construction can function within a larger construction. While a construction with the status of PROCESS can function as a clausal head, a construction with the status of ATEMPORAL RELATION can modify a noun. The possibilities are illustrated in Table 18.2.
Observe that the clausal examples all contain a modal verb. This makes it easier to show the clausal head independently from the grounding predication. As this pattern illustrates, the only example that is not well-formed concerns the penultimate combination, where PERF4 is restricted to co-occurring with the perfect auxiliary have. As Langacker observes, this model of the verb string explains why auxiliaries and their participles have to occur in pairs within a clause: have V-PERF4 make a perfect construction (e.g.have betrayed); be1 V-ing make a progressive construction (e.g. be betraying); and be2 V-PERF3 make a passive construction (e.g. be betrayed). The reason why these elements have to occur in pairs within the clause is because each construction headed by the participle (without its auxiliary) has the status of an ATEMPORAL RELATION. While this can occur as modifier, it cannot occur as a clausal head. Therefore the auxiliary verb is required to contribute its own profile to the construction, which then has the status of a PROCESS and can head a clause. Of course, as we will see in more detail below (section 18.3), the PROCESS profile contributed by the auxiliary still requires grounding (by a modal or a tense morpheme), which explains why a non-finite auxiliary cannot occur as the first element in a verb string (e.g. *George have betrayed Lily).
