淺談as引導(dǎo)的非限制性定語從句的形式特點(diǎn) 1. _is known to everyone, the moon travels round the earth once every moth. A. ItB. AsC. ThatD. What 正確答案應(yīng)選B項(xiàng)。這是一道由as引導(dǎo)的非限制性定語從句的語法題。在句中，as為關(guān)系代詞，在從句中作主語，代表整個(gè)主句the moon travels round the earth once every month。在形式上，從句與主句用逗號(hào)隔開。此句譯為：正如人們所知的那樣，月球每個(gè)月繞地球一周。在實(shí)際做題時(shí)，許多學(xué)生錯(cuò)誤地選擇了答案A項(xiàng)，原因在于他們沒有搞清楚此類句型的特點(diǎn)。 2. _ is known to everyone that the moon travels round the earth once every month. A. ItB. AsC. ThatD. What 正確答案應(yīng)選A項(xiàng)。初看起來，此題與上題相似，但實(shí)際上有著較大的差別。此句屬于名詞性從句中的主語從句。在句中，It為形式主語，that引導(dǎo)主語從句the moon travels round the earth once every month。形式上沒有逗號(hào)隔開。此句譯為：月球每個(gè)月繞地球一周是人們所共知的。 為了讓大家能更好地理解和掌握as引導(dǎo)的非限制性定語從句，現(xiàn)舉例予以說明： （1）The compass, as is well-known to all, was invited in ancient China. 眾所周知，指南針是中國古時(shí)發(fā)明的。 （2）He seems a farmer, as in actual fact he is. 他看上去像個(gè)農(nóng)民，事實(shí)上他就是農(nóng)民。 （3）As we know, Taiwan is a part of China.正如我們所知道的，臺(tái)灣是中國的一部分。（as在從句中作know的賓語，代表主句Taiwan is a part of China） 從以上句子可以看出，as引導(dǎo)的非限制性定語從句具有以下特點(diǎn)： （1）其先行詞可為整個(gè)主句，也可為某一個(gè)名詞。 （2）as在從句中可以作主語、表語或賓語。用作主語時(shí)，謂語動(dòng)詞用單數(shù)形式。 （3）其從句可以放在主句的前面或后面，也可以放在整個(gè)句子中間。也就是說從句可以位于句首、句中或句末，但習(xí)慣用逗號(hào)隔開。 （4）as仍有“正如那樣；像一樣；由而知”等作連詞時(shí)的詞義。 （5）在句法上，as常被用作一些實(shí)義動(dòng)詞的表語及其被動(dòng)語態(tài)的主語，如see, know, say, report, imagine, show, remember, point out等動(dòng)詞。常見的詞組有： as is well known to all / as we all know 眾所周知 as has been said before 如上所說 as you expected 如你所料 as has been already reported 據(jù)報(bào)道可知 as she imagined 如她所想像的那樣 as it showed 正如所反映的那樣 as anybody can see 正如人們所看到的那樣 as除了能引導(dǎo)非限制性定語從句外，還能引導(dǎo)限制性定語從句。常與the same或such連用，構(gòu)成：the sameas, suchas。as引導(dǎo)限制性定語從句時(shí)，在從句中同樣可以作主語、表語或賓語。如： （1）Such Chinese as is spoken in Shanxi is not Putonghua. We call it the Shanxi dialect.在陜西說的漢語不是普通話，我們稱為陜西方言。（as在從句中作主語） （2）I have the same book as you have. 我的書和你的一樣。（as在從句中作have的賓語） （3）He is not such a clever person as she is. 他不像她那樣聰明。（as在從句中作is的表語）【就遠(yuǎn)原則】謂語動(dòng)詞與前面主語一致 代表詞匯：as well as；（together/along/combined）with；rather than；except；besides；but；including；in addition to；apart from；like ；as much as ；no less than例如：Nobody but two students is in the classroom.除了這兩個(gè)學(xué)生,沒有人在教室 Everybody except you is down on me.除了你,大家都看不起我.A woman with two children has come.一位婦女帶著兩個(gè)孩子已經(jīng)來了.John, rather than his roommates, is to blame.約翰,而不是他的室友,應(yīng)該受到責(zé)備.Jim , together with his classmates ,has seen the film. 吉姆和他的同學(xué)都看過這部電影.My father, no less than I, is a base-ball fan.我的父親不亞于我也是個(gè)棒球迷.The son, as well as his parents, wants to go there.不但兒子想去那兒,而且他的父母也想去.The teacher, as well as the students, is interested in the activity.老師也和同學(xué)們一樣對(duì)這項(xiàng)活動(dòng)有興趣【就近原則】由下列詞語連接的并列主語：there be+句型; or ; either or；nor; neithernor；whetheror；notbut; not onlybut also ; 等. What he does or what he says does not concern me.他的行為或言談都與我無關(guān). Neither you nor I am wrong .你和我都沒錯(cuò). Not you but your father is to blame.不是你,而是你的父親該受責(zé)備. Not only you but(also) he is wrong.不僅你錯(cuò)了,他也錯(cuò)了.which與as引導(dǎo)非限制性定語從句的異同一、相同點(diǎn)兩者引導(dǎo)非限制性定語從句時(shí)，可指代主句中的部分或整個(gè)句子的內(nèi)容，在從句中做主語，賓語或表語，位于主句之后有時(shí)可互換。The meeting was put off, as /which was exactly what we wanted.He was a doctor, as/which I knew from his manner.二、不同點(diǎn)1. as可以放在主句前后，也可插入主句之中；而which引導(dǎo)的非限制性從句只能位于主句之后。As is known to all, fish cant live without water.Air, as we know, is gas.2.在非限制性從句中，which后的be動(dòng)詞不可??；as而后的be動(dòng)詞可以省略。She told me she won the match, which was a lie.The material is elastic, as (was) shown in the figure.3. which在非限制性定語從句做主語時(shí)可用各類動(dòng)詞做謂語；而as做主語時(shí)，謂語常用系動(dòng)詞，如be, seem, become等，一般不用其他行為動(dòng)詞。He saw the girl, which delighted him.He didnt say anything at the meeting , as/which seemed very strange.4. as常用“正如”含義，常用的結(jié)構(gòu)有as we know（眾所周知）；as often happens（正如常發(fā)生的那樣）；as is often the case（情況常常如此）; as we all can see（正如我們看到的）; be announced/expected/known/imagined/mentioned/said/shown/reported等。這些結(jié)構(gòu)常放句首，偶爾也可以放句中或句末。As is known to all, China is a developing country.Kate was late for school, as often happened.5. 在非限制性定語從句中which指代主句中某一個(gè)單詞時(shí)，as不可以。My brother enjoyed playing basketball, which he really plays well.Beijing, which he was born in, is our capital.6. “介詞+關(guān)系代詞（介賓代物）”中關(guān)系代詞只能用which。The Travel Agency, with which our company has been dealing for several years, has opened for new branches. Air is a mixture of gases, of which oxygen forms 21 percent.7. 從句中的謂語動(dòng)詞是