The grammatical terms clause and phrase are often confused by English speakers. This lesson filled with clauses and phrases will help you understand the difference.
A clause is a group of words including a subject and a predicate. The subject is the person or thing performing the action of the verb in the predicate, while the predicate is that verb plus, optionally, additional information such as the object of the verb or an adjective describing the subject.
He looks happy.
We love pancakes!
I might be crazy.
The above examples are all independent clauses, because they are stand-alone sentences. A sentence can have more than one independent clause – shown here in italics.
Birds fly and fish swim.
He looks happy but you seem sad.
A clause that depends on another clause to complete its meaning is called a dependent clause or subordinate clause. Dependent clauses cannot stand alone; their meaning is dependent upon an accompanying independent clause. In these examples, the dependent clauses are in italics. As you can see, if you remove the non-italicized words, the sentence is incomplete.
I don’t know how birds fly.
Tell me if he looks happy.
We’re going to IHOP because we love pancakes!
He thinks (that) I might be crazy.
A phrase is any group of words that form a unit of meaning within a sentence. There are different types of phrases depending on what part of speech the most important word – called the headword – belongs to.
Noun phrases include a noun plus a determiner and/or an adjective:
any big store
some yellow cars
Prepositional phrases consist of a preposition plus the object of that preposition.
inside the store
behind closed doors
on top of a mountain
Adjectival phrases are made up of an adjective plus an adverb and/or a prepositional phrase.
covered in dust
very happy about it
The Bottom Line
Both clauses and phrases are groups of words, but clauses must include at minimum a subject and verb. If they are independent clauses, they are stand-alone sentences. Phrases have neither a subject nor a predicate, though they might function as either one. Phrases are never stand-alone sentences.
The big red house is on Maple Street.
The above sentence is an independent clause. The big red house is a noun phrase which serves as the subject of the clause, and on Maple Street is a prepositional phrase which, combined with the verb is, forms the predicate of the clause.
It’s good that you are so happy about it.
It’s good is an independent clause and that you are so happy about it is a dependent clause. So happy about it is an adjectival phrase which contains the prepositional phrase about it.
Note that both clause and phrase have other meanings outside of linguistics which are not covered here.