Phrase and clause both have multiple meanings. We’ll focus first on how they refer to grammatical units of language; then we’ll look briefly at their other uses.
Phrases include any groups of words that form grammatical and meaningful units that are not clauses or sentences. Here are some examples:
The little green men (a noun phrase)
Eat pancakes with syrup (a verb phrase)
At the right time of year (a prepositional phrase)
The groups of words above form complete syntactic and meaningful units. Each has a grammatical category (e.g., noun phrase, verb phrase, etc.). The grammatical category determines the way they can be used in sentences.
The following are NOT phrases:
pancakes with
at the
time of
These are not phrases because they are not meaningful or grammatical units. If you are unsure whether a group of words is a phrase or not, the best test is substitution—to replace the group of words with one word; if you can substitute, it’s a phrase; take the following example:
[The little green men] [eat pancakes with syrup] [at the right time of year].
We can replace [The little green men] with They, or Friends, or Men, etc. and it’s still a good sentence (i.e., it still makes sense). Similarly, we could replace [eat pancakes with syrup] with the word eat, and we could replace [at the right time of year] with yearly.
Note that phrases are often composed of smaller phrases:
The little green men from Alpha Centauri that I met last week . . .
The above is one phrase. You can substitute it for “the little green men” in the original sentence. But within this phrase, there are many smaller phrases:
little green men
green men
from Alpha Centauri
Alpha Centauri
I (the subject, “I”)
met last week
last week
The above are all phrases. The following are not phrases:
from
Alpha Centauri that
that I
Clauses are complete sentences, but not all sentences are clauses. Clauses are always made of a noun phrase and a verb phrase (except for imperative clauses—see below). Here, the clauses are in bold, with the noun phrases underlined, and the verb phrases in italics:
Children play.
Hopefully, the girl I invited will come to my party.
We will be late and we are bringing a friend.
Please, don’t stay in bed all day unless you want to fail.
As you can see, mostly everything is part of a clause, except for sentence-level modifiers, such as hopefully and please; conjunctions such as and and unless; and complementizers, like that.
Notice that, as with phrases, we can have clauses inside clauses:
[Tell her that [I said that [she is beautiful.]]]
In this case, she is beautiful, I said that she is beautiful, and the whole sentence are all clauses.
Other Meanings of “Phrase” and “Clause”
Now, let’s look at some other uses of the words phrase and clause:
Phrase
A unit of melody (a group of musical notes that forms a complete rhythmic and meaningful unit); the smallest meaningful units of music.
As a verb, to phrase means “to express in specific words,” (e.g. What is the best way to phrase this idea?)
Clause
A section of a law, contract, or other formal document that expresses a complete idea; for example:
Clause 42.c: Landlords are not permitted to evict a tenant without 30-days notice in writing.