Complements and adjuncts

The last example, bought a present for Jeanie in Jenners last Tuesday, brings us to the second major distinction. Modifiers fall into two classes – obligatory modifiers, known as complements, and optional modifiers, known as adjuncts. The distinction was first developed for the phrases that modify verbs, and indeed applies most easily to the modifiers of verbs; we will focus on verbs, but the distinction is also applied to the modifiers of nouns. Before discussing the division of modifiers into complements and adjuncts, we must take the example at the beginning of this paragraph and convert it to a complete clause, say My mother bought a present for Jeanie in Jenners last Tuesday. We saw from (6a–c) that the verb controls whether a direct object is excluded, required or merely allowed.

From these examples, we might conclude that the verb controls only the phrases that follow it; but the verb can be seen as controlling every other phrase in the clause. (My) mother in the revised example above is the subject of the verb. As will be demonstrated, the subject of a clause plays an important role; nonetheless, in a given clause the verb controls the subject noun too. Bought requires a human subject noun; that is, it does in everyday language but behaves differently in the language of fairy stories, which narrate events that are unconstrained by the biological and physical laws of this world.

A verb such as flow requires a subject noun denoting a liquid; if in a given clause it has a subject noun denoting some other kind of entity, flow imposes an interpretation of that entity as a liquid. (Of course, some entities can be either liquids or solids; molten steel flows, solid steel does not.) Thus people talk of a crowd flowing along a road, of traffic flowing smoothly or of ideas flowing freely. Such talk offers a view of the crowd moving along a road held in by the buildings on either side and propelled by a mysterious motive force, just as a river moves along in a mysterious fashion held in by its banks. What we are considering is the distinction between literal language and figurative or metaphorical language. The distinction will not be explored here, but it is important to be aware that many of the constraints which linguists discuss apply to literal language but dissolve in figurative language.

Returning to the clause My mother bought a present for Jeanie in Jenners last Tuesday, we will say that the verb bought controls all the other phrases in the clause and is the head of the clause. It requires a human noun to its left, here mother; it requires a noun to its right that denotes something concrete (although we talk figuratively of buying ideas in the sense of agreeing with them). It allows, but does not require, time expressions such as last Tuesday and place expressions such as in Jenners. Such expressions convey information about the time when some event happened and about the place where it happened. With verbs, such time and place expressions are always optional and are held to be adjuncts. The major exception is BE, which has its own syntactic patterns. Phrases that are obligatory are called complements. (The term ‘complement’ derives from a Latin verb ‘to fill’; the idea conveyed by ‘complement’ is that a complement expression fills out the verb (or noun and so on), filling it out or completing it with respect to syntax but also with respect to meaning. The term ‘adjunct’ derives from the Latin verb ‘join’ or ‘add’ and simply means ‘something adjoined’, tacked on and not part of the essential structure of clauses.) All verbs in English declarative clauses require a noun to their left; even where the buyers are known, they must be mentioned by means of a noun. Verbs such as BUY also require a noun to their right. Without one, the clause in which they occur is incomplete and the message conveyed by the clause is incomplete for speakers of English.