つい

つい is an adverb meaning "unintentionally," "accidentally," or "against one's better judgment." It describes actions that happen without the speaker meaning to do them – often out of habit, impulse, or carelessness. The speaker typically knows they shouldn't have done something (or didn't plan to), but it happened anyway.

Unintentional actions / habits

つい is used when someone does something out of habit or without thinking.

Against one's better judgment

つい often conveys the nuance that the speaker knew better but still did the action – similar to "I couldn't help but…" or "I ended up…" in English.

Often paired with ～てしまう

つい frequently appears together with 〜～てしまう (or its casual form ～ちゃう), which reinforces the sense of regret or that the action was completed unintentionally.

つい vs. うっかり

Both つい and うっかり can mean "accidentally," but they differ in nuance. つい implies the speaker was driven by impulse or habit – they were somewhat aware but couldn't stop themselves. うっかり implies carelessness or absent-mindedness – the speaker simply forgot or wasn't paying attention.