Clauses: Clauses are groups of words that contain both a subject and a predicate. They can be independent (expressing complete thoughts) or dependent (relying on another clause for meaning).
Phrases: Phrases are groups of related words that function as a single unit within a sentence. They do not have both a subject and predicate like clauses do.
Sentence Structure: Sentence structure refers to how sentences are organized grammatically. It includes elements such as subject-verb agreement, punctuation usage, and the arrangement of phrases and clauses within the sentence.