What is the distinction between a phrase and a sentence?

Answer 1

A sentence requires a subject and predicate. That means a noun and a verb that are in agreement with one another (in terms of singular and plural). A phrase is not a complete sentence. It is a little group of words that go together and function together in some way.

Here is a very short but complete sentence:

She laughs.

You have a subject (a pronoun, which stands "for" ["pro"] a noun) and a verb that agrees with it--that is, both are singular.

Here is a very long phrase that is not a complete sentence. This happens to be a prepositional phrase because it begins with a preposition ("in") and ends with the object of the preposition (the noun "house"). All the rest is description of the noun at the end.

in the large, ramshackle, isolated, abandoned, and allegedly haunted house

(You would not really write like this, we hope, but it would be a correct and grammatical phrase if you did.)

If you have a subject and a verb that make a complete sentence, you can't call it a phrase. If all you have is a phrase, you don't have a sentence.

Answer 2

A phrase is a group of words that does not have both a subject and a predicate, and thus does not express a complete thought. In contrast, a sentence is a group of words that contains a subject and a predicate, forming a complete thought or idea. Sentences are the building blocks of communication, while phrases serve to add detail or context to sentences.