21. But for + n. / pron., sb. / sth. would (not) have done..要不是.,某人早就(表示虛擬語氣)=If it had not been for..,./If there had not been ..

　　22. It won(t) be long before +從句(從句中用一般現在時)不久/很久就要.

　　It was (not) long before+從句(從句中用一般過去時)不久/很久才..

　　23. Those who.(從句及主句中謂語動詞用復數形式).

　　Anyone who= Whoever..(從句及主句中謂語動詞用單數形式)

　　24..主句(一般現在時或過去時)...when從句.(might/ should do 或might / should have done) 表示對比,意思為 本該(可)而卻,主句中為陳述語氣,從句里為虛擬語氣

　　Eg: Why are you here when you should be in school?你本該上學的怎么在這兒?

　　He stopped trying when he might have succeeded .本該已成功了他卻停止努力了.

　　25. There is ./ Sb. have no doubt that(同位語從句,that不可省略) 毫無疑問

　　There is / Sb. have some doubt whether..(同位語從句不可用if)不確定是否

　　Sb. Doubt if / whether. 某人懷疑是否

　　Sb. dont doubt that 某人不懷疑

　　26.immediately / directly / instantly / the moment +從句

　　on / upon + n. / doing

　　No sooner had sb. done than .(過去時)

　　Hardly had sb. done when..(過去時)

　　注意：這幾個結構都表示一.就

　　27. every time / each time / the last time / the first time / next time +從句(名詞性短語引導一個時間狀語句)

　　anywhere / everywhere +從句(相當于wherever引導的地點狀語從句)

　　Eg: You can go anywhere you like.

　　Next time you come, please bring your son along.

　　28.Ifonly / I wish +從句(用過去類時態) 表示虛擬語氣, 要是.就好了 但愿就好了!

　　29.Considering+ n. 或 pron. 或 that從句 / Seeing that.考慮到/鑒于.

　　Given + n. / pron.作狀語,表示 在有的情況下 如果有 假定,有時也表示考慮到

　　Eg: Seeing (that) he refused to help us, there is no reason why we should help him now.

　　Given good health, I hope to finish the work this year.

　　Given their inexperience / that they are inexperienced, theyvedone a good job.

　　30.Therewas a time when.曾經有那么一度.

　　31.otherthan與no, not, none等否定詞連用,表示肯定意思,如:

　　Eg: It was none other than Mr. Smith.這正是Smith先生.

　　32. Not until.did / do/ does / will sb. do

　　It was / is not until that sb

　　33.Its(un) like sb. to do / to have done做某事很像某人/ 做某事可不像某人

　　34.Itremains to be seen Wh--words ..是否.還有待于看.(不用that, if作連接詞)

　　35.Itonly remains for sb. to do剩下的只是要某人做某事.

　　Eg: Weve got everything ready. It only remains for you to come to dinner.

　　36.Onemoment., and now剛才一會兒還在做而現在卻..

　　37.Notall / both / everyone表示部分否定

　　38. Such is / are..這(些)就是.(謂語動詞單復數由后面名詞決定)

　　39.Id rather (not) do / have done我寧愿..

　　Id rather +從句(從句中用過去時或過去完成時)

　　40. Its important / necessary / strange / surprising.+that(用陳述語氣或should do)

　　41. I like / hate / appreciate it that / when等從句 (it表示后面從句的這種情況)

　　Eg: I appreciate it if you will give me a hand.

　　42. By the time +從句(一般現在時/過去時)，主句(將來完成時/過去完成時)

　　43.,as is often the case with sb. / as is usual with sb.(as引導非限制性定語從句)

　　44 in case / lest / for fear that.(從句中用陳述語氣或shoulddo)

　　45.While置于句首可表示As long as 或 Although

　　Eg: While there is life there is hope.

　　While I admit his good points, I can see his bad ones.

　　46. cannot ( never) too +adj. (adv. ) / adj. (adv.) + enough 越越好非常

　　too + adj. ( anxious / eager / willing / ready / glad等)+todo.表示肯定意思

　　Eg: I cant thank you enough.我非常感激你.

　　He was too glad to see his father.=He was very glad to see his father.

　　47. not /never等表示否定的詞與比較級連用表示最高級，如：

　　Eg:-----Do you agree with his suggestion?

　　-------I cant agree more.

　　48. What if..要是.怎么辦?

　　Eg: What if he doesntt come tomorrow?

　　49. more..than與其.不如..

　　Eg: He is more nervous than frightened.

　　50. It is/ has been +一段時間+since從句(從句中如為延續性動詞,則實際表示的意思相反)

　　Eg: It is two years since he drank.他不喝酒已兩年了.

　　21. But for + n. / pron., sb. / sth. would (not) have done..要不是.,某人早就(表示虛擬語氣)=If it had not been for..,./If there had not been ..

　　22. It won(t) be long before +從句(從句中用一般現在時)不久/很久就要.

　　It was (not) long before+從句(從句中用一般過去時)不久/很久才..

　　23. Those who.(從句及主句中謂語動詞用復數形式).

　　Anyone who= Whoever..(從句及主句中謂語動詞用單數形式)

　　24..主句(一般現在時或過去時)...when從句.(might/ should do 或might / should have done) 表示對比,意思為 本該(可)而卻,主句中為陳述語氣,從句里為虛擬語氣

　　Eg: Why are you here when you should be in school?你本該上學的怎么在這兒?

　　He stopped trying when he might have succeeded .本該已成功了他卻停止努力了.

　　25. There is ./ Sb. have no doubt that(同位語從句,that不可省略) 毫無疑問

　　There is / Sb. have some doubt whether..(同位語從句不可用if)不確定是否

　　Sb. Doubt if / whether. 某人懷疑是否

　　Sb. dont doubt that 某人不懷疑

　　26.immediately / directly / instantly / the moment +從句

　　on / upon + n. / doing

　　No sooner had sb. done than .(過去時)

　　Hardly had sb. done when..(過去時)

　　注意：這幾個結構都表示一.就

　　27. every time / each time / the last time / the first time / next time +從句(名詞性短語引導一個時間狀語句)

　　anywhere / everywhere +從句(相當于wherever引導的地點狀語從句)

　　Eg: You can go anywhere you like.

　　Next time you come, please bring your son along.

　　28.Ifonly / I wish +從句(用過去類時態) 表示虛擬語氣, 要是.就好了 但愿就好了!

　　29.Considering+ n. 或 pron. 或 that從句 / Seeing that.考慮到/鑒于.

　　Given + n. / pron.作狀語,表示 在有的情況下 如果有 假定,有時也表示考慮到

　　Eg: Seeing (that) he refused to help us, there is no reason why we should help him now.

　　Given good health, I hope to finish the work this year.

　　Given their inexperience / that they are inexperienced, theyvedone a good job.

　　30.Therewas a time when.曾經有那么一度.

　　31.otherthan與no, not, none等否定詞連用,表示肯定意思,如:

　　Eg: It was none other than Mr. Smith.這正是Smith先生.

　　32. Not until.did / do/ does / will sb. do

　　It was / is not until that sb

　　33.Its(un) like sb. to do / to have done做某事很像某人/ 做某事可不像某人

　　34.Itremains to be seen Wh--words ..是否.還有待于看.(不用that, if作連接詞)

　　35.Itonly remains for sb. to do剩下的只是要某人做某事.

　　Eg: Weve got everything ready. It only remains for you to come to dinner.

　　36.Onemoment., and now剛才一會兒還在做而現在卻..

　　37.Notall / both / everyone表示部分否定

　　38. Such is / are..這(些)就是.(謂語動詞單復數由后面名詞決定)

　　39.Id rather (not) do / have done我寧愿..

　　Id rather +從句(從句中用過去時或過去完成時)

　　40. Its important / necessary / strange / surprising.+that(用陳述語氣或should do)

　　41. I like / hate / appreciate it that / when等從句 (it表示后面從句的這種情況)

　　Eg: I appreciate it if you will give me a hand.

　　42. By the time +從句(一般現在時/過去時)，主句(將來完成時/過去完成時)

　　43.,as is often the case with sb. / as is usual with sb.(as引導非限制性定語從句)

　　44 in case / lest / for fear that.(從句中用陳述語氣或shoulddo)

　　45.While置于句首可表示As long as 或 Although

　　Eg: While there is life there is hope.

　　While I admit his good points, I can see his bad ones.

　　46. cannot ( never) too +adj. (adv. ) / adj. (adv.) + enough 越越好非常

　　too + adj. ( anxious / eager / willing / ready / glad等)+todo.表示肯定意思

　　Eg: I cant thank you enough.我非常感激你.

　　He was too glad to see his father.=He was very glad to see his father.

　　47. not /never等表示否定的詞與比較級連用表示最高級，如：

　　Eg:-----Do you agree with his suggestion?

　　-------I cant agree more.

　　48. What if..要是.怎么辦?

　　Eg: What if he doesntt come tomorrow?

　　49. more..than與其.不如..

　　Eg: He is more nervous than frightened.

　　50. It is/ has been +一段時間+since從句(從句中如為延續性動詞,則實際表示的意思相反)

　　Eg: It is two years since he drank.他不喝酒已兩年了.