たら、かえって

Usage

Used to express regret about past

漢字が書けない。学生の時、もっと勉強すればよかった I can't write Kanji. I should have studied harder when I was a student

頭がいたい。昨日あんなにお酒を飲まなければよかった I have a headache. I shouldn't have drunk so much yesterday