sentences

A sentence is a linguistic unit that typically expresses a complete thought and can function as a statement, question, command, or exclamation. In written language, sentences are usually marked by terminal punctuation such as a period, question mark, or exclamation point.

Most sentences have a subject and a predicate, where the subject is the noun phrase that refers to what is being talked about, and the predicate contains the verb and information about what the subject does or is. Not all languages require an explicit subject; some are pro-drop. Word order varies: English often follows subject–verb–object, but many languages use SOV, VSO, or other orders and can rely on case marking or particles to indicate grammatical roles.

Sentence types can be classified by function or by structure. By function, sentences are declarative (statements), interrogative (questions), imperative (commands), or exclamative (exclamations). By structure, they can be simple (one independent clause), compound (two or more independent clauses joined by conjunctions), complex (one independent clause and at least one dependent clause), or compound-complex (two or more independent clauses with at least one dependent clause).

Punctuation marks signal sentence boundaries and aid interpretation, though usage varies across languages. Some languages permit ellipsis or clausal subordination that changes surface form without altering core meaning.

Linguistically, sentences express propositional content and speaker intent; they interact with semantics to convey truth-conditions and with pragmatics to indicate discourse function and illocutionary force.