Phrases

Constituency

How do we know that phrases exist? In saying that intermediate levels between the word and the clause are significant in English grammar we are asserting that within a clause there can be smaller groups of words that belong together. In order to judge whether a string of words forms a phrase we can make use of a number of tests:

• Substitution. If a string is a constituent it will be possible to substitute another string and keep the sentence grammatical. For example, in the clause I left my green umbrella at your house the string my green umbrella is a constituent since we can substitute the pronoun it and keep a grammatical reading: I left it at your house. The string left my green is not a constituent since there is nothing that can be grammatically substituted in its place.

• Movement. If a string is a constituent of a clause it may be possible to move the constituent around in the clause. For example, the clause Every Monday night I wash my hair works just as well ordered I wash my hair every Monday night. This tells us that every Monday night is a constituent. Note that English word order imposes some restrictions on movement so this test should not be used alone. For example, my hair is a constituent (try the substitution test to check) but it cannot be moved around to the same degree (*My hair every Monday night I wash). This is because an object such as my hair in this example must always follow the verb unless a more complex sentence structure such as extrapositioning (My hair, every Monday I wash it) is used.

• Conjoinability. Only constituents can be joined together using coordinators such as and because coordination requires like constituents to be of the same type. For example, in the clause My favourite ways to travel are by train and by tram, two prepositional phrases (by train, by tram) are joined together.

Head words and dependents

Each phrase is named after its head word. The head word is the word that the phrase is required to have in order to exist. Many types of phrases (noun phrases, verb phrases, adjective phrases and adverb phrases) can contain a single word but a small number of phrases always have dependents. For example, prepositional phrases normally have depenents since prepositions generally require a noun phrase to follow.

Different types of phrases have different types of dependents. Complements are dependents within a phrase that are necessary for the phrase to be grammatical. Thus, a prepositional phrase (PP) consists of a preposition as the head of the phrase and a noun phrase (NP) complement because prepositions are not usually grammatical on their own. For example, from the dentist contains the preposition from and the NP the dentist. A sentence that only had the preposition from is not grammatical (for example, *I came home from).

Many phrase types allow modifiers. Adjective phrases function as modifiers within noun phrases (for example, I found some lovely green shoes). Modifiers are optional dependents; the clause is grammatical whether they're there or not (for example, both I found some shoes and I found some lovely green shoes are grammatical clauses).