IV. FACT IN THE PAST -> IF CLAUSE (TYPE 3)
3. We got lost because we didn't have a map.
-> If.....................................................................
4. We stayed up late last night and we were so tired.
-> If......................................................................
5. He wasn't able to answer the questions, so he failed the exam.
-> If.......................................................................
3 we had had a map, we wouldn't have got lost.
4 we hadn't stayed up late last night, we wouldn't have been so tired.
5 he had been able to answer the questions, he wouldn't have failed the exam.
-Câu điều kiện loại 3 diễn tả điều không thể xảy ra ở quá khứ: If + S + V(quá khứ hoàn thành), S + would/could + have + PII+......
