What you need is more practice

　　What is hard is to do good all one’s life and never do anything bad.

　　Whatever was said here must be kept secret.

　　Whatever I have is at your service.

　　Whoever comes will be welcome.

　　Whoever fails to see this will make a big blunder.

　　由連詞that引起的主語從句: 這類主語從句在大多數情況下都放到句子后部去, 而用代詞it做形式上的主語:

　　That we need more equipment is quite obvious.

　　It is impossible that I may not able to come.

　　It doesn’t seem likely that she will be here.

　　在口語中連詞that有時可以省略掉:來源：考試大考試大成就你的夢想

　　It’s good you’re so considerate.

　　It’s a pity you missed such a fine talk.

　　由連接代詞或連接副詞(或whether)引起的主語從句: 這類主語從句, 也可以放到句子后部去, 前面用it做形式上的主語.

　　When we shall have our sports meet is still a question.

　　It is still a question when we shall have our sports meet.

　　Whether he will join us won’t make too much difference.

　　It won’t make too much difference whether he will join us.

　　2賓語從句: 和主語從句及表語從句一樣, 賓語從句也有以上三類.

　　a) 連接代詞或副詞引導的從句只是在某些動詞后能用作賓語.

　　Tell me what you want.

　　I just can’t imagine how he could have done such a thing.

　　Have you decided whom you are to nominate as your candidate.

　　能跟這類賓語從句的常見動詞有: see, say, tell, ask, answer, know, decide, find out, imagine, suggest, doubt, wonder, show, discover, discuss, understand, inform, advise等. 這種動詞后也常用whether或if引導的從與作賓語:

　　I don’t know whether these figure are accurate.

　　I’m wondering if the letter is overweight.

　　這種從句有時前面可以有另一個賓語:

　　Has she informed you when they are to hold the meeting?

　　Please advise me which book I should read first.

　　有時這種從句也可用作及詞的賓語:

　　Whether that is a good solution depends on how you look at it.

　　He was not conscious of what an important discovery he had made.

　　I was curious as to what he would say next.

　　b) 用that引導的從句作賓語的情形最為普遍, 在很多動詞如boast, say, think, insist, wish, hope, suppose, see, believe, agree, acknowledge, admit, deny, expect, explain, confess, order, command, suspect, dream, suggest, propose, know, mean, notice, prefer, request, require, report, urge, 以及doubt的否定和疑問式后面都可以用它.