Whetherclause

Whetherclause is a linguistic term referring to a finite dependent clause headed by the complementizer whether. It encodes an embedded yes-no question or an alternative proposition and is used in a variety of syntactic contexts. In English, examples include “I wonder whether he will come” and “Please decide whether to attend.” Such clauses can function as the object of verbs like know, think, or ask, or as the subject of a sentence (“Whether he will come is unclear.”). The embedded clause generally maintains the word order of a declarative sentence, with no subject–auxiliary inversion, unlike many direct questions.

Distinctions: whetherclause contrasts with if-clauses in many grammars. Both can introduce embedded questions, but whether is favored when the question contains alternatives (whether or not) or when two or more possibilities are contrasted, or in formal style (for example, “We are uncertain whether the policy will pass”). If-clauses are common after verbs of thinking or hoping, but they do not always replace whether in all contexts.

Semantics and syntax: whetherclauses express doubt, contingency, or inquiry. They can scope over negation, conditionals, or future events, and may appear in indirect question reporting, condition statements, or as complement clauses after adjectives such as certain, doubtful, or possible.

Cross-linguistic note: many languages have a dedicated yes-no-question complementizer or an equivalent form to signal yes-no questions; some rely on mood or syntactic position rather than a dedicated complementizer.