Student or Learner
could you please tell me what is the difference?
is a "sentence" a kind of "phrase".
in order to keep things simple, could I always use "phrase"?
A sentence can be defined as an entity consisting of a group of words starting with a capital letter and ending in a fullstop, a question mark or an exclamation mark. One important thing in a sentence is that it has a verb.
She goes to school everyday.
A phrase is a group of wrods that have a head and a modifier.
A good boy = Noun Phrase because it has a head noun (boy) and two pre-modifiers: a + good
at school = Prepositional Phrase because it has a head Preposition (at) + prepositional complement (school)
Very good = is an adjectival phrase (Good= Head Ajective , very= premodifier "adverb")
You cannot refer to a phrase and a sentence interchangeably. However, if you want to refer to any of them you can simply say: "an utterance"