只是 is a common two-character conjunction or adverb meaning 'merely', 'just', or 'nothing more than'. It combines 只 (zhǐ), meaning 'only' or 'just', and 是 (shì), meaning 'to be'—together, they function as a fixed expression emphasizing limitation or understatement. Unlike the verb 是 alone, 只是 does not assert identity but rather downplays significance, intention, or scope. It often appears at the beginning or middle of a sentence to soften statements, express modesty, or clarify that something is not as serious, complex, or consequential as it might seem.

This word frequently occurs in spoken and written Chinese to convey humility, reassurance, or gentle correction. For example, when apologizing or explaining, speakers use 只是 to signal that an action was minor or unintentional. It can also introduce a contrastive clause (e.g., 'It’s just…, not…'), making it useful for nuanced, polite communication. Note that it is never used before nouns as a determiner—unlike English 'just', it doesn’t modify nouns directly but modifies verbs, adjectives, or entire clauses.