If it were not for ……

　　結(jié)構(gòu)︰if it were not for+名詞/子句，主詞+would/should 等+原形動(dòng)詞…

　　說明︰此句型意為“若非（有）…”。此類句構(gòu)專門用于表示與現(xiàn)在事實(shí)相反的。亦可用“but for+”或“without+”代替。were 可以提前，省略 if，如例句3.

　　If it were not for his presence， I would punish you. 要不是他在場，我會(huì)處罰你的。

　　But for your advice， I should have failed. 要不是你的忠告，我會(huì)失敗的。

　　But for music （=Were it not for music）， life would be dull. 要不是音樂，人生會(huì)很無聊。

　　If it were not for oxygen and nitrogen in the air， no man could live on the earth.

　　大氣中如果沒有氧和氮，人就無法生存于地球了。

　　Without air， all living things would die. 若非空氣，所有的生物都會(huì)死亡。

　　Without newspaper， we would get behind the times. 要不是報(bào)紙，我們都趕不上時(shí)代了。

　　I should be lonely， were it not for the birds and the flowers. 我會(huì)寂寞，若非有鳥也有花。

　　Were it not for his help， I could not finish the work.若非有他的幫助，我就不能完成這件工作。

　　Were it not for science， we could not live a comfortable live.

　　若非科學(xué)，我們無法過著舒適的生活。

　　If it had not been for ……

　　結(jié)構(gòu)︰if it had not been for+名詞/子句，主詞+would/should 等+原形動(dòng)詞…

　　說明︰此句型意為“若非（有）…”。此類句構(gòu)專門用于表示與過去事實(shí)相反的。

　　If it had not been for his help， I should have failed. 如果沒有他的幫忙，我應(yīng)該已經(jīng)失敗。

　　Had it not been for your timely help， our company would have been on the verge of bankruptcy. 若非你及時(shí)伸出援助之手，本公司將會(huì)瀕臨破產(chǎn)的邊緣。

　　If it had not been for these experiments， the improvement of the machine would have been impossible. 要不是這些實(shí)驗(yàn)，這部機(jī)器也許就不可能改良了。

　　Had it not been for the kind guide， I might have got lost in the mountains.

　　要不是這位好心的向?qū)�，我可能就在山中迷路了�?/p>

　　If it had not been that he was here， I would have punished you.

　　要不是他在場，我當(dāng)時(shí)就會(huì)處罰你。

　　I demand/insist that ……

　　結(jié)構(gòu)︰主詞1+意志動(dòng)詞（demand/insist 等）+（that）+主詞2+（should）+原形動(dòng)詞

　　說明︰意志有四類：建議（suggest，recommend，propose，advise，urge 等），要求（desire， ask，demand，require，request，maintain，insist 等），命令（order，command 等），規(guī)定（ rule，regulate，stipulate 等）其后接 that-時(shí)，該里的要用原形或“should+”。美式英語通常省略 should.

　　The committee moved that the meeting （should） be adjourned. 委員提議休會(huì)。

　　His parents demanded that he （should） be back by ten. 他的父母要求他十點(diǎn)以前回家。

　　The employees demand that their salaries be raised. 員工們要求加薪。

　　They ruled that the law （should） not be imposed. 他們規(guī)定不應(yīng)加重法律。

　　His father ordered that he （should） keep a diary in English.

　　他的父親規(guī)定他要用英文寫日記。

　　My mother encouraged me and insisted that I continue my education.

　　我媽媽鼓勵(lì)我，而且堅(jiān)持我應(yīng)該繼續(xù)我的教育。

　　He insisted that I （should） apologize to her. 他堅(jiān)持我應(yīng)該向她道歉。

　　Recently， many states have insisted that high schools teach students how to drive.

　　最近，許多州堅(jiān)持中學(xué)應(yīng)該教學(xué)生如何開車。

　　His father insisted that they （should） move to the country. 他爸爸堅(jiān)持他們應(yīng)該搬到鄉(xiāng)下。

　　It is proper …… that ……

　　結(jié)構(gòu)︰It is+意志形容詞（important 等）+（that）+主詞+（should）+原形動(dòng)詞

　　說明︰意志包括 important，necessary，imperative，essential，urgent，desirable， advisable，recommendable，proper 等。that-中只能用 should，不可用 must，而 should 往往予以省略。

　　It is necessary that he （should） sort out the information for my reference.

　　他有必要整理些資料供我參考。

　　It is essential that he get up early. 他有必要早起。

　　It is urgent that food and clothing （should） be sent to the sufferers.

　　急需將食物和衣服送給災(zāi)民。

　　It is desirable that we （should） provide for the poor at Christmas.

　　在圣誕節(jié)施舍窮人是可喜的事。

　　It is important that he be quiet. 他該保持安靜是有必要的。

　　It is important that he not do it. 他不該做那事是有必要的。

　　It is requested that all members be present at the party. 全體會(huì)員都被要求出席這次晚會(huì)。

　　It is proper that such a bad man be punished severely. 這么壞的人受重罰是應(yīng)該的。

　　Imperative Sentence + Conj. + Main Clause