quickly

Quickly is an adverb that denotes high speed or rapidity in the performance of an action. It describes how something is done, rather than what is done, and is commonly used to indicate speed, urgency, or immediacy in both everyday and formal contexts.

Typically, quickly modifies a verb: “She ran quickly.” It can appear before the main verb for emphasis: “She quickly ran to the door.” In many contexts, it also follows auxiliary verbs: “They have quickly realized the mistake.” The placement can vary to achieve a particular emphasis or rhythm in a sentence.

Compared with fast, quickly is more tightly linked to manner and action rather than a static state. Fast can function as both an adjective and an adverb in informal usage (“go fast”), while quickly remains the standard form in formal prose when describing the pace of an action.

Etymology traces quickly to the adjective quick, from Old English cwic meaning alive or living, with -ly forming the adverb. Over time, quick developed a sense of speed, and quickly emerged as the adverbial form used to modify verbs and clauses.

Usage notes: in formal or precise writing, choosing a specific verb or a more precise adverb can convey pacing more clearly (for example, “arrived within minutes” rather than “arrived quickly”). Be mindful of collocations and avoid redundant phrases such as “quickly and rapidly” unless stylistically intended. Common collocations include “move quickly,” “think quickly,” and “act quickly.”