like Eliot and Legz said, - Your sentences are Not correct: " is my sentence is correct "ㅎㅎㅎ what is that mean, it's mean hahaha" .....correct or not ?" Correct: Is my (this) sentence correct? " 'ㅎㅎㅎ', What does that mean; does it mean hahaha?" or "What does 'ㅎㅎㅎ' mean? Does it mean hahaha?" - Yes, 'ㅎㅎㅎ'　means hehehe, hahaha, etc. (Do you know that's Korean, not English?)

"Ha" = 하, but I think "ㅎ ㅎ ㅎ" still represents laughter. "ㅋ ㅋ ㅋ" is laughter, too.

It's totally wrong. 1. What does this mean? 1. It means hahaha.