強(qiáng)調(diào)句與從句的比較
1. 強(qiáng)調(diào)句與主語(yǔ)從句的比較
強(qiáng)調(diào)句將句子中的it is / was …that同時(shí)省去，句子仍然成立；而主語(yǔ)從句將that與后面部分代替it，成立。如：
(1) It is Li Lei's brother that you met in the street yesterday. 你昨天在街上所見(jiàn)到的就是李蕾的兄弟。
本句若將It is 及 that同時(shí)省去為：You met Li Lei's brother in the street yesterday. 句子同樣成立，因此前面的句子是強(qiáng)調(diào)句型。
(2) It is exciting that we have succeeded in sending up Shenzhou V. 我們成功地發(fā)射了神舟五號(hào)這件事情真令人興奮。
本句若將It is 及 that同時(shí)省去為：We have succeeded exciting in sending up Shenzhou V. 顯然句子錯(cuò)誤，因此，前面句子不是強(qiáng)調(diào)句型，而是主語(yǔ)從句。
2. 強(qiáng)調(diào)句與定語(yǔ)從句的比較
◎強(qiáng)調(diào)句中的It沒(méi)有實(shí)際意義，It be與that可同時(shí)被省略；而定語(yǔ)從句中的It是主語(yǔ)，It be與that不可同時(shí)省略；
◎強(qiáng)調(diào)句型中be的時(shí)態(tài)須跟后面句子的時(shí)態(tài)相一致；而定語(yǔ)從句中主句謂語(yǔ)動(dòng)詞be的時(shí)態(tài)須由主句的時(shí)間確定；
◎強(qiáng)調(diào)句將句子中的that不能省略，并且即使前面的名詞是事物時(shí)，也不能將that換成which；而定語(yǔ)從句中的that作賓語(yǔ)時(shí)可被省略，并且當(dāng)先行詞是事物時(shí)可用which代替。
◎當(dāng)it be后面的時(shí)間、地點(diǎn)名詞作主語(yǔ)、賓語(yǔ)或表語(yǔ)時(shí)，引導(dǎo)詞可用that / which；而作其他成分時(shí)，引導(dǎo)詞須用when / which。如：
(1) It is an English book (that / which) I bought yesterday. 它是我昨天買的書(shū)。(本句是對(duì)What is that?問(wèn)句的回答，that所引導(dǎo)的是定語(yǔ)從句，that可被省略)
It was the English book that I bought yesterday. 昨天我所賣的就是這本書(shū)。(本句相當(dāng)于對(duì)I bought the English book yesterday中an English book進(jìn)行強(qiáng)調(diào))
(2) It was a room where we used to have meetings. 它是我們過(guò)去常在開(kāi)會(huì)的房子。(where 所引導(dǎo)的從句對(duì)前面的room進(jìn)行說(shuō)明，它是定語(yǔ)從句 www.yingyuyufa.com)
It was in the room that we used to have meetings. 過(guò)去我們開(kāi)會(huì)就在這間房子里。(in the room是被強(qiáng)調(diào)的部分，本句是強(qiáng)調(diào)句型)
(3) It is a day when the people celebrate their victory. 這是人們慶祝他們的勝利的日子。 (when所引導(dǎo)的從句對(duì)a day進(jìn)行說(shuō)明，是定語(yǔ)從句)
It was on that day that people celebrated their victory. 就在那一天，人們慶祝了他們的勝利。(強(qiáng)調(diào)on October 1, 1949)
3．強(qiáng)調(diào)句與狀語(yǔ)從句的比較
◎狀語(yǔ)從句句首的It本身就是句子的主語(yǔ)；而強(qiáng)調(diào)句首的It不作任何成分也沒(méi)有實(shí)際意義。
◎狀語(yǔ)從句的連接副詞that及句子前面的It be不能去掉。
◎狀語(yǔ)從句的引導(dǎo)詞可以是when / where，而強(qiáng)調(diào)句型中的that不能用其他詞代替。如：
(1) It is such an interesting book that we all like it very much. 它是一本如此有趣的書(shū)，我們大家都非常喜歡。(結(jié)果狀語(yǔ)主從復(fù)合句)
It is such an interesting book that we all like very much. 我們大家都非常喜歡的就是一本如此有趣的書(shū)。(強(qiáng)調(diào)such an interesting book)
(比較：It is such an interesting book as we all like very much. 這就是我們大家都非常喜歡的如此有趣的書(shū)。定語(yǔ)從句)
(2) It was already morning when he woke up. 當(dāng)他醒來(lái)時(shí)，已經(jīng)是早晨了。(時(shí)間主從復(fù)合句)
It was the next morning that he woke up. 就在第二天早晨他醒來(lái)了。(強(qiáng)調(diào)the next morning)