1．條件句中：
 If it were not for…；If it hadn’t been for…這兩種句型表示“要是沒有”,相當(dāng)于but for
If it had not been for the PLA man,he would not be studying English now.
 if…only…（或If only…）表示“要是…就好了”
1．名詞性從句：
 demand/suugest/order/insist/propose/request/ask/advise/prefer/command/desire that…
They demanded that the aggressor troops (should) be withdrawn immediately.
由insist引導(dǎo)的賓語從句可以虛擬也可以不虛擬：
He insisted that he was right.堅(jiān)持認(rèn)為
He insisted that we should agree with him.堅(jiān)持某事
由suggest引導(dǎo)的賓語從句可以虛擬也可以不虛擬：
His white face suggests that his not healthy.表明
He suggested that we have a rest.建議
If I could only see him once!
If only I had listened to your advice.很明顯,這種句型省略了主句
2．其他狀語從句中：
 as if/as though/even if…
Tom looked sad as if he had heard bad news.
I won’t lend you any money even I had money.
3．名詞性從句：
 wish that…（hope后的賓語從句不虛擬）
I wish I were as strong as you.
How I wish it wasn’t raining!
 would rather/would sooner/had rather that…表示“寧愿”
I would rather they came tomorrow.
I could go myself but I would sooner you went.
I had rather you told him than I did.
 It is time/high time that…
It is time we went to bed.
+(should) do：
if only:要是...多好
Examples:
1.If only he had been here.
要是他當(dāng)時(shí)在這兒就好了.
2.I dread the coming exams.If only I could have time to review my lessons.
我對(duì)即將到來的考試非常擔(dān)心.如果我有時(shí)間復(fù)習(xí)該有多好啊.
3.If only I had another chance.
要是我再有一次機(jī)會(huì)就好了.
4.I am so tired.If only I can take the day off tomorrow.
太疲倦了.如果明天能不上班多好.
5.If only problems would come one at a time!
要是問題一次只發(fā)生一個(gè)該多好!
6.If only it clears up,we'll go.
只要天一放晴,我們就去.
7.If only one had an unlimited supply of money!
要是財(cái)源不斷就好了!
8.She would be a very good player if only she could get it together.
她若能控制得當(dāng)就能成為很好的選手.