Phrases focus on nouns, while clauses are centered around verbs. Clauses must have a subject and a verb, unlike phrases, which lack them.
Phrases are centered around nouns, such as 'in the van' or 'by early morning.' Clauses are centered around verbs, like 'she runs the marathon' or 'when he saw the ruins.'
All clauses must contain both a subject and a verb while phrases lack either a subject, a verb, or both. There are main (independent) clauses that can stand alone and convey an idea, as well as subordinate (dependent) clauses that rely on another part of the sentence for meaning.