only

Only is a versatile English word used to restrict or limit what is described. It can function as an adverb, determiner, adjective, or conjunction, depending on context. In its core sense, it marks exclusivity or limitation: She is the only person here; I only want to help.

Etymology and history: The word originates in Old English as an adjective meaning alone or sole, from a root idea of being one. It later evolved to its current adverbial and determiner functions, extending its role from describing a state to modifying verbs, adjectives, and entire clauses.

Grammatical roles and usage: As an adverb, only limits the action or description, and its placement can shift emphasis. Examples include I only explained the plan and I explained the plan only, where the scope changes with position. As a determiner or modifier, only precedes a noun to express exclusivity, as in the only option or an only child. As an adjective, only can describe a noun directly in phrases like an only son, though this usage is less common in modern prose. As a conjunction or discourse marker, only can introduce a conditional or restricted idea, as in Only if you study will you pass.

Nuances and style: Only interacts with word order to determine emphasis, and its misplacement can alter meaning. It is often substituted with synonyms such as solely, merely, or exclusively, depending on the desired tone. In informal speech, placement may be flexible for emphasis but can cause ambiguity in written text.

See also: exclusivity, sole, merely, exclusively.