A phrase is a key grammatical unit and so is something you need to get to grips with. A phrase is a group of words that shares a close relationship. This means that a phrase acts as a unit with individual meaning, but without being sufficiently complete in its meaning to form a clause or sentence .
A phrase acts in the same way as a single word - which means it can act as if it were a noun, adverb, verb, etc.
Note that some grammarians often refer to single words as phrases.
A nounphrase always has a noun as its head word, e.g. "a cat"; "the naughty cat"; "that furry black mangy old cat".
Verbphrase (sometimes called a verb chain)
A verbphrase always has a verb as its headword, "drink"; "has drunk"; "has been drinking"; "seems"; "will be"; "might have been"; "explained"; "has been explaining".
Adjectivephrase (or adjectivalphrase)
An adjective phrase always has an adjective as its headword, e.g. "gory", "absolutely foul".
Adverbphrase (or adverbialphrase)
A phrase with an adverb as its head word, e.g.soundly; too evidently; as quickly as possible
Prepositionalphrase (a special kind of adverbialphrase)
A phrase which has been constructed from a preposition with a noun phrase linked to it to form a single unit of meaning, e.g. "up the road"; "across the street"; "round the bend".
Phrases - with words - are the basic building blocks of clauses and sentences. A phrase can always be split into two parts: its head word which is linked to some kind of modification of the head word. The head word is the central part of the phrase and the remaining words act to modify this head word in some way, e.g. "The peculiarly strong creature" - can you see that the headword of this nounphrase is the noun, "creature"?
As suggested above, a phrase does, in fact, act just like an individual word. The next example sentence contains three phrases and a single main clause. Can you recognise which are the phrases and which is the clause?
In a frenzy, without thinking, he grabbed him by the neck.
You might like to think that, between each word of the three phrases above, there exists a kind of “word glue” that gives the phrase its coherent quality. The phrases "In a frenzy", "without thinking" and "by the neck" all can be seen to exist as individual units of meaning, i.e. as individualphrases.
Notice that the clause in the above sentence cannot be called a phrase because it is built around a verb (i.e. a verbphrase), "he grabbed him"