違いない
ちがいない · chigainai · JLPT N3 · expression
sure
🎯 違い (difference, mistake) + ない (none) = no mistake about it, so it's certain
違い is the noun form of 違う, to differ or be wrong. Add ない and it means there's no room for error. It often follows a guess to show strong conviction, as in 彼に違いない, it must be him.