淺談同位語(yǔ)從句和定語(yǔ)從句的區(qū)別
在教學(xué)中,同位語(yǔ)從句和定語(yǔ)從句是個(gè)難點(diǎn).為了幫助老師和同學(xué)們解決這個(gè)難點(diǎn),現(xiàn)就同位語(yǔ)從句和定語(yǔ)從句的區(qū)別談?wù)勛约旱囊稽c(diǎn)看法.同位語(yǔ)從句和定語(yǔ)從句都放在被修飾詞的后邊,從形式上來(lái)看,它們十分相似.從以下幾個(gè)方面來(lái)談它們的區(qū)別.
1、從句所修飾詞的不同.同位語(yǔ)從句所修飾詞通常是少數(shù)一些表示抽象意義的名詞,如belief , doubt , fact , hope , idea , news , possibility , thought , order , suggestion , wish , answer , information , conclusion , decision , discovery , knowledge , law , opinion , problem , promise , proof , question , report , truth , risk 等.定語(yǔ)從句的先行詞可以指人、物等.例如：
He has told us a fact that drinking too much does harm to our health.他又告訴我們一個(gè)事實(shí),過(guò)渡飲酒對(duì)健康有害.(同位語(yǔ)從句)
We have no idea that her mother was a professor ten years ago. . 我們不知道她的母親十年前是個(gè)教授.(同位語(yǔ)從句)
This is the book that I bought yesterday. 這是我昨天買的那本書(shū).（定語(yǔ)從句）
I will never forget the day when I joined the Party. 我將永遠(yuǎn)不會(huì)忘記我入黨的那一天.（定語(yǔ)從句）
2. 連接詞的作用不同.連接同位語(yǔ)從句的that只起連接作用,不在從句中擔(dān)任任何句子成分.whether 和 how 可以引導(dǎo)同位語(yǔ)從句,但不能引導(dǎo)定語(yǔ)從句.關(guān)系代詞和關(guān)系副詞除了連接從句的作用外,還在定語(yǔ)從句中充當(dāng)一定的句子成分,如主語(yǔ)、賓語(yǔ)、定語(yǔ)、表語(yǔ)等.引導(dǎo)定語(yǔ)從句的連接詞是關(guān)系詞,常見(jiàn)的關(guān)系代詞和關(guān)系副詞有that , which , who , whose , whom , when , where , why , as,than, but 等.
The news that he wants to get is whether he will be sent to the countryside.他所想得到的消息是他是否將被派往農(nóng)村.(定語(yǔ)從句,關(guān)系代詞that作從句get的賓語(yǔ).)
Do you have a doubt whether she will be dismissed from school? 你懷疑她是否能被學(xué)校開(kāi)除嗎?(同位語(yǔ)從句)
I have no idea how his parents were sad on hearing that their son was killed in the earthquake. 我不知道他的父母一聽(tīng)到他在地震中陣亡是多么悲傷!(同位語(yǔ)從句)
3. 從句作用的不同.定語(yǔ)從句具有形容詞或副詞的特點(diǎn),對(duì)先行詞起修飾、限定作用,描述先行詞的性質(zhì)或特征,與先行詞之間是所屬關(guān)系.同位語(yǔ)從句具有名詞的特點(diǎn),對(duì)中心詞作進(jìn)一步補(bǔ)充解釋,是中心詞的具體內(nèi)容.例如：
The man that you saw just now is my bother. 你剛才看到的那個(gè)人是我的弟弟.(定語(yǔ)從句)
The suggestion that the meeting be put off proved right.推遲會(huì)議的建議證明是正確得.（同位語(yǔ)從句）
The suggestion that he had made is that the meeting be put off. 他提出的建議推遲會(huì)議.（定語(yǔ)從句）
4. 正確理解和使用同位語(yǔ)從句,還應(yīng)注意以下幾點(diǎn)：
A.分隔同位語(yǔ)從句：有時(shí)同位語(yǔ)從句與其先行詞被其它成分分隔開(kāi)來(lái),這種分隔主要出于修辭原因,即為了保持句子結(jié)構(gòu)平衡,避免頭重腳輕.
The whole truth came out at last that he was a wolf in sheep‘s clothing . 真相終于大白了,他原來(lái)是只披著羊皮的狼.
An order has come from Beijing that these thieves will be sentenced to death .
B.在某些名詞后的同位語(yǔ)從句中,其謂語(yǔ)動(dòng)詞應(yīng)用虛擬語(yǔ)氣形式：（should） + 動(dòng)詞原形.常見(jiàn)的名詞有advice , idea , order , demand , plan , proposal , suggestion , request 等.例如：
The suggestion that a new bridge (should) be built was accepted . 采納了在這里修建一座新橋的建議.
C.同位語(yǔ)從句的先行詞往往沒(méi)有復(fù)數(shù)形式.例如：
他要來(lái)教我們英語(yǔ)的消息昨天我就聽(tīng)說(shuō)了.
（正）The message that he would teach us English reached me yesterday .
（誤）The messages that he would teach us English reached me yesterday .