套用俗話“人比人，氣死人”，這“詞比詞”也就可以說是“暈死人”了。尤其是when遇到了while，又遇到了as，這三個(gè)詞可謂是詞匯用法比較中的經(jīng)典了。三個(gè)詞都同屬于一家“公司”——“時(shí)間狀語從句集團(tuán)”，又在外“兼職”，各有他用。因此，有時(shí)要分清楚這三個(gè)詞何時(shí)在“司何職”，就頗費(fèi)力氣?，F(xiàn)在我們就在這期微語法中將它們拉出來溜溜，看看到底有哪些不同。

首先來看一看，這三個(gè)詞在時(shí)間狀語從句中的區(qū)別：

第一， when，while，as均可表示時(shí)間段，意思是“在……期間”，和進(jìn)行式連用，此時(shí)從句中謂語動(dòng)詞為延續(xù)性動(dòng)詞。其中when和as也可表示時(shí)間點(diǎn)，意思是“在那時(shí)，當(dāng)時(shí)”，和一般時(shí)連用，此時(shí)從句中謂語動(dòng)詞為瞬間動(dòng)詞，而while不能表示時(shí)間點(diǎn)，其從句謂語動(dòng)詞也不能是瞬間動(dòng)詞；When可表示“同時(shí)發(fā)生”或“先后發(fā)生”；While只可表示“同時(shí)發(fā)生”；As可表示“同時(shí)發(fā)生”或無明顯先后的“接連發(fā)生”。

1. ______ I was walking down the street， I met several street artists.

A. When B. While C. As D. As soon as

此題ABC都是正確答案，當(dāng)主句動(dòng)作“met”的時(shí)間區(qū)間屬于從句動(dòng)作“was walking”的時(shí)間區(qū)間時(shí)，when，while，as均可使用，本句的時(shí)間側(cè)重于“走在街上的那段時(shí)間內(nèi)”。D項(xiàng)as soon as傾向于“發(fā)生動(dòng)作或事情的那個(gè)時(shí)刻”，不選。

第二，以下四種情況只用when，不用while/as：（1）長動(dòng)作中的短動(dòng)作（包括when表示“就在此時(shí)”的情況）；（2）兩個(gè)短動(dòng)作先后發(fā)生；（3）人生中的某一時(shí)期；（4）when 的意思等于 each/every time 時(shí)。

2. I was taking a shower ______ the fire broke out.

A. when B. as C. while D. after

此題選A，洗澡是長動(dòng)作，起火是在洗澡期間內(nèi)發(fā)生的短動(dòng)作。似乎此處的when就是經(jīng)常提及的“就在此時(shí)”，但在此句：___ the teacher came in， we were reading中，橫線處也只能填when，因?yàn)槔蠋熯M(jìn)來相對于我們讀書是一個(gè)短動(dòng)作，但此處若譯成“就在此時(shí)”又顯牽強(qiáng)，所以用“長動(dòng)作中的短動(dòng)作”的邏輯來判斷，更有助于理解。

3. Victor lost his left leg ___ he was twelve.

A. as B. while C. when D. during

此題選C，指人生中過去的某一時(shí)期。

4.___you talk to someone or write a message， you show your skills to others.

A. While B. As C. By the time D. When

此題選D，when在題意中相當(dāng)于every time或者each time。

第三，以下兩種情況不用while，但可以具體選用when和as。（1）兩個(gè)短動(dòng)作同時(shí)發(fā)生時(shí)，可用when或as。（2）兩件事情同時(shí)發(fā)生變化時(shí)或表示“隨時(shí)間推移”的概念時(shí)，以及表示“一邊……一邊……”的意義時(shí)，通常用as。

5. the temperature increases， the volume of water becomes greater.

A. When B. As C. While D. Since

此題答案選B，兩件事情同時(shí)發(fā)生變化。

第四，下列情況通常用while或as，不用when：兩個(gè)明顯的長動(dòng)作同時(shí)發(fā)生時(shí)，如 I was watching TV，my mother was cooking in the kitchen，這兩個(gè)動(dòng)作都較長，故橫線上填while/as更為恰當(dāng)。

第五，下列情況常用when和while，不用as：從句謂語動(dòng)詞是表示狀態(tài)的動(dòng)詞時(shí)，常用when或者while，此時(shí)如果用as則表示原因，不表時(shí)間。

6. —I’m going to the post office.

— you are there， can you buy me some stamps？

A.As B.while C.Because D.If

此題CD兩項(xiàng)很好排除，答案選B。此題很明顯表示的是時(shí)間概念，as時(shí)間狀語從句不能有狀態(tài)動(dòng)詞are，宜用while而不用as。如強(qiáng)用as，則表示原因，與句意不符。

7. His eyesight became worse he grew older.

A. after B. as C. while D. when

此題則恰恰相反只能選as，句中g(shù)rew為系動(dòng)詞，雖有“變化”之意，但還是一種長區(qū)間狀態(tài)，as此時(shí)和其連用只表原因，不表時(shí)間。類似的詞包括所有系動(dòng)詞以及諸如know，love等通常不能用進(jìn)行時(shí)表達(dá)的狀態(tài)動(dòng)詞，此句應(yīng)譯為“因?yàn)槟昙o(jì)大了，所以視力變差了?！庇行┱Z法講解中，將該句視為時(shí)間狀語從句，翻譯成“當(dāng)他年紀(jì)大了，視力變差了”似乎也沒有問題，但其實(shí)此處只能選擇as的根本原因，可以理解為那是因?yàn)閍s在此處是原因狀語從句，讀者可以將例7和例題5、例題6進(jìn)行比較揣摩。

接著，我們來看一下這三個(gè)詞的非時(shí)間狀語從句用法：

8.You can’t win the game when（在……情況下）you never practice during this period.

9.It was foolish of you to take a taxi when（在……情況下）you could easily walk there in five minutes.

例題8和例題9，when的這一用法是近年的高考新寵兒，有多種譯法，筆者將其譯作“在……情況下”，更有助于理解，但不表示“條件”，此種when用法強(qiáng)調(diào)的是并列事實(shí)間的對比差異。再如：They had only three chairs when they need five。

10. While（雖然） all of them are strong candidates，only one will be chosen for the post.

11.The first two are free while（而）the third costs $30.

12.Try as（盡管，表讓步） he might，little Tom couldn’t get the door open.

13. He travels a lot，as（正如，表方式）do most of the people who have become rich.

14.I am ashamed，sir，that I wasted a lot of hours when（定語從句關(guān)系副詞）I should have studied in class.

好吧，這三個(gè)詞的比較，只要掌握了這些，就ok了，那趕快趁熱打鐵吧！Strike while the iron is hot！

配套練習(xí)

1. Debbie was about to close the window her attention was caught by a bird perching on the window sill.

A. when B. if C. and D. till

2. volleyball is her main focus， she’s also great at table tennis.

A. Since B. Once C. Unless D. While

3. It just isn’t fair I was working as a waiter last month； my friends were lying on the beach.

A whenever B. though C. for D. while

4. He joined the army he left home.

A. when B.as C. while D. where

5. The volume varies the temperature increases.

A. when B. while C. during D. as

6. the sun rose， the fog dispersed.

A. While B. When C. As D. During

7. Because of the heavy traffic，it was already time for lunch break she got to her office.

A. since B. that C. when D. until

8. Mary got married to an American she was in college.

A. as B. when C. while D. during

9. We always sing we dance.

A. as B. while C. when D. as soon as

10. Mary made coffee her guests were finishing their meal.

A. so that B. although C. while D. as if

11. Mr. Black’s ankle aches it starts to rain.

A. when B. while C. after D. during

12. he is a top student，he has some shortcomings.

A. As B. While C. When D. Since

13. He usually walks he might ride.

A. when B. unless C. while D. as

14. Kids talk frequently about what they can do，

many adults do the opposite，tending to talk about what they can’t .

A. when B. as C. while D. where

15.Child Tom is，he has been a success.

A. when B. although C. while D. as

16.Why does she always drive she could easily walk to the company？ It’s a little bit strange.

A. while B.as C. when D. unless

參考答案：1—16 ADDAD CCBAC ABACD C