1 He didn't revise all his lessons, he can't do the exercise => If he .... 2 If she sees Peter tomorrow, she'll tell him to come here => Should .... 3 If I were to the party, I would meet him => Were .... 4 If Rosie hadn't stayed up late last night, she wouldn't feel tired now => Had .... 5 He would have lent you his bike if you had asked him => Had ....

`1.` If he had revised all his lessons, he could have done the exercise.

`-` Vì đề bài cho thì Quá Khứ Đơn ( didn't revise - didn't + Vinf ) nên ta dùng câu điều kiện loại 3 để diễn tả tình huống trái thực tế trong quá khứ.

`-` Công thức : If + S1 + had + past participle, S2 + would/might/could… + have + past participle  

`2.` Should she see Peter tomorrow, she'll tell him to come here.

`-` Đảo ngữ câu điều kiện loại 1 : Should + S1+ (not) + V (nguyên thể), S2 + will/may/can/should/... + Vinf

`3.` Were I to the party, I would meet him.

`-` Đảo ngữ câu điều kiện loại 2 :  Were + S1 + (not) + O, S2 + would/could.. + Vinf

`4.` Had Rosie not stayed up late last night, she wouldn't feel tired now.

`-` Đảo ngữ câu điều kiện loại 3 : Had + S1 + (not) + past participle, S2 + would/might/could… + have + past participle

`-` Vì vế sau có now ( bây giờ ) `->` dùng câu điều kiện loại 2 để diễn tả tình huống giả định, không thể xảy ra ở hiện tại, không có thực ở hiện tại.

`5.` Had you asked him, he would have lent you his bike.

`-` Đảo ngữ câu điều kiện loại 3 : Had + S1 + (not) + past participle, S2 + would/might/could… + have + past participle