1. Unless we protect the environment, we will destroy ourselves.
⇒If we don't protect the environment, we will destroy ourselves.
2. Unless she is more hard-working, she will get low marks.
⇒If she isn't more hard-working, she will get low marks.
3. Unless he listens to his parents, he will fail.
⇒If he doesn't listen to his parents, he will fail.
4. They began watching the movie one hour ago.
⇒They have watched the movie for one hour
5. He last cried ten years ago.
⇒He has never cried for ten years
1. Unless we protect the environment, we will destroy ourselves.
⇒If we don't protect the environment, we will destroy ourselves.
2. Unless she is more hard-working, she will get low marks.
⇒If she isn't more hard-working, she will get low marks.
3. Unless he listens to his parents, he will fail.
⇒If he doesn't listen to his parents, he will fail.
4. They began watching the movie one hour ago.
⇒They have watched the movie for one hour
5. He last cried ten years ago.
⇒He has never cried for ten years
Dựa vào cấu trúc câu:
So sánh nhất : S + to be + the most + adj + O
So sánh hơn : S1 + tobe + more adj + than + S2
Thì hiện tại hoàn thành : S + have/has + PII
Câu điều kiện loại 1 : S + hiện tại đơn , S + will/won't + V