also: ったら · だら
particle, conjunction
Conditional particle/conjunction attaching to the past tense of verbs, adjectives, and the copula. Expresses a hypothetical or temporal condition ('if/when X happens, then Y'). The form だら appears after voiced sounds in casual speech.
雨が降ったら、試合は中止です。
If it rains, the game will be canceled.
家に着いたら電話してください。
Please call me when you get home.
particle
when it comes to ...; as for ...; that ...
Colloquial topic particle expressing light scorn, annoyance, or surprise about the marked topic. Often used with ったら for emphasis. Similar to 'speaking of ...' or 'that ...' with an emotional tone.
あの人ったら、また遅刻だよ。
That guy, he's late again.
この部屋ったら、すごく散らかってるね。
This room, it's so messy!
particle
hey; vocative particle
Colloquial vocative particle used to call someone's attention with frustration or impatience. Usually ったら. Attaches to a name or noun.
お母さんったら、早く来て！
Mom, come quick!
太郎ったら、返事しなさいよ。
Taro, answer me!
と is a conditional particle expressing a natural or inevitable consequence, while たら can be used for hypothetical or less certain conditions.
Derived from the classical Japanese perfective auxiliary たり (tari) in its conditional form たらば (taraba), which contracted to たら (tara). The colloquial emphatic variants ったら and だら developed through phonetic shifts in spoken Japanese.