'刚刚' is an adverb meaning 'just now' or 'a moment ago', emphasizing that something happened very recently—often within seconds or minutes. Though composed of two identical characters (刚), the reduplication intensifies the sense of immediacy, making it stronger and more emphatic than the single character '刚'. It functions as a time adverbial, typically placed before the verb in a sentence, and is commonly used in both spoken and written Chinese to convey freshness of timing.

This word often appears in conversational contexts—like reporting recent events, answering questions about timing ('When did you arrive?'), or expressing surprise at how recent something was. It never refers to future time and cannot modify nouns directly; it always relates to completed actions. Its tone and rhythm give it a natural, colloquial feel, especially when paired with perfective aspect markers like '了'.