if I were you
私が君だったらそんな事はしないだろうよと彼は私に言った。
He told me that if he were me, he wouldn't do such a thing.
私が君だったら、もっと一生懸命勉強するでしょう。
If I were you, I would study harder.
私が君だったら、そんな無礼なことをしたりしないでしょう。
If I were you, I wouldn’t do something so rude.
もし私が君だったらすぐ帰宅するだろう。
If I were you, I would go home right away.