This is the 13848th most frequent Korean word.
만났으면
"만났으면" means "if (someone) met."
The term '만났으면' is used to express a past hypothetical condition: 'If I had met'.
그를 더 일찍 만났으면 좋았을 텐데.
I wish I had met him earlier.
Here, '만났으면' indicates a completed action with a conditional consequence: 'If met' or 'having met'.
만났으면 이제 인사를 해야지.
Since you have met, you should greet now.
In this sentence, '만났으면' expresses speculation about an unrealized past event: 'Had we met'.