❶ If I had known you were my teacher today、I would’ve brought my other material.
(あなたが今日私の先生だと知ってたら、他の資料も持ってきたのに)。
❷ If I knew you were my teacher today, I would’ve written down questions to ask you.
(あなたが今日私の先生だと知ってたら、あなたに聞きたかった質問を書いてきたのに)。
❸If I knew you were teaching me today, I would’ve brought my homework from school.
(あなたが今日私に教えてくれるって知ってたら、学校の宿題も持ってきたのに)。
If I knew you were my teacher today は「あなたが今日私の先生だと知ってたら」です。
I would've は 私は〇〇したのに〜と言う意味です。
〜参考までに!