主語從句是在主句中做主語的句子。它由連接詞引導，通常位於謂語動詞前。Your words make him angry.
What you said makes him angry.
通常在從句中不做任何成分。有三個：that, whether 和if。
※whether 和if 不做任何成分，但有”是否”的意思。
常有：who, whom, whose, what, which, whoever, whomever, whatever, whichever. ※在從句中常做主語、賓語、表語或定語。
常有：when, where, why, how, whenever, wherever, however.
1. Whether we will win depends on ourselves.
2. That he got the first prize excited us all.
3. What we should do with the problem is undecided.
4. I’m wondering whatever you said made him so angry.
5. What worries us most is who let out the secret.
6. How they will solve the serious problem has not been decided.
7. Why he did that wasn’t quite clear.
8. Where we can look up his address is still a question.
9. It is quite clear that the whole project is to be a failure.
10. It is likely that there will be a snowstorm tomorrow.
11. It’s no wonder that you have achieved so much success.
12. It is a pity that you didn’t attend their wedding.
13. It is said/reported/announced that the plan has been cancelled.