吉晨春

摘? ? 要：主題句在英語說明文概要寫作中的作用十分重要。主題句是段落主旨所在，綜合各段主題句可知全文大意。英語說明文概要寫作可以借助說明文的篇章結(jié)構(gòu)特點與段落展開方式，定位與提煉主題句，從詞、句、語法以及釋義的角度轉(zhuǎn)述主題句，從而個性化地表達(dá)主旨。

關(guān)鍵詞：說明文;概要寫作;段落主題句;定位;提煉

概要寫作要求學(xué)生用自己的語言精準(zhǔn)、連貫地寫出所讀文章的主旨大意。作為高考英語概要寫作常用文體之一的英語說明文有開門見山的特點，即在起始段或?qū)а圆糠纸沂疚恼轮黝}或闡述要說明的對象，隨后的正文部分往往從不同的側(cè)面、角度對說明對象進(jìn)行具體說明，結(jié)尾段一般對說明對象再進(jìn)行總的概括性說明。導(dǎo)言部分是主題所在。

說明文段落常由主題句和發(fā)展句或擴(kuò)展句構(gòu)成。主題句用來概括需要說明的事物、事理的特征，表達(dá)主題內(nèi)容;發(fā)展句用來具體闡述事因、由來、利弊、功能、用途等。主題句與發(fā)展句的關(guān)系是上下關(guān)系，是概述與細(xì)說的關(guān)系，是結(jié)論與支撐的關(guān)系，它們相互依存[1]。當(dāng)然，有的段落可能沒有主題句，需要讀者加以提煉。

主題句是段落主旨所在，綜合各段主題句便可知說明文全文大意。由此可見，準(zhǔn)確定位和提煉主題句是說明文概要寫作的前提或保證，而用自己的語言個性化地轉(zhuǎn)述主題句、表達(dá)主旨，則是說明文概要寫作的關(guān)鍵。

一、主題句的定位與提煉

英語說明文段落的展開方式有多種。根據(jù)高中生英語學(xué)習(xí)的基礎(chǔ)和認(rèn)知水平，本文主要討論在以特定順序和以不同句式開頭的兩種段落展開方式下如何定位和提煉主題句。

（一）段落以特定順序展開說明

1.邏輯順序

邏輯順序是說明文段落最主要的展開方式，即按照事物或事理的內(nèi)部聯(lián)系形成人們認(rèn)識事物的過程來說明[2]。一般分為四種：演繹法（從一般到具體）、歸納法（從具體到一般）、歸納—演繹法（從具體到一般再到具體）和演繹—歸納法（從一般到具體再到一般）。

（1）演繹法

段落以從一般到具體的形式展開。作者在開頭表明段落的中心思想，而后進(jìn)行闡釋論證，分點說明，最后得出結(jié)論，回應(yīng)主題思想。這時，主題句在段首，后面的句子是擴(kuò)展句。

例1? ?Written Chinese has also become an important means by which Chinas present is connected with its past. People in modern times can read the classic works which were written by Chinese in ancient times. The high regard for the Chinese writing system can be seen in the development of Chinese characters as an art form， known as Chinese calligraphy， which has become an important part of Chinese culture.

【解析】主題句在段首，后面擴(kuò)展句圍繞主題句分兩個層次展開具體說明。

（2）歸納法

段落采用由具體向一般或概括發(fā)展的模式，即表述具體細(xì)節(jié)的句子在前，概述總結(jié)性的句子在后。這時，主題句置于段尾，前面的句子為擴(kuò)展句。

例2? ?Rescue workers are trained to find people. Treat injuries， and hand out food， water， and other supplies. They have to be able to do work that is difficult under conditions which can be very dangerous. After a disaster， there is usually no electricity or water， and there may be diseases and accidents. Rescue workers get to save lives， but they must also bury the dead. That means they have to be strong in both body and mind.

【解析】本段前部分文字說明救援隊員的工作內(nèi)容以及所遇到的危險、疾病、事故等狀況。最后一句將前面講到的具體細(xì)節(jié)進(jìn)行提煉概括：救援隊員在身體和精神兩方面的素質(zhì)都得過硬。顯然，最后一句是主題句，前面的句子都是擴(kuò)展句，為后面的主題句作鋪墊。

（3）歸納—演繹法

段落以“歸納—演繹”的形式展開，開頭以有關(guān)細(xì)節(jié)或證據(jù)的句子為主題鋪墊，隨后歸納提煉出主題思想或觀點，接著再用演繹法補充句子對主題加以論證。這時，主題句在段落中間。

例3? ?Everyone has heard of accountants， salespeople， and lawyers. But have you ever heard of a kiss mixer or a belly builder？ Most jobs have common titles， but there are also many unusual position titles. A kiss mixer， for instance， is the person who mixes the ingredients for candy kisses. And a belly builder is the individual who assembles and fits the inside parts of pianos.

【解析】首句介紹common titles for jobs，第二句提出有關(guān)a kiss mixer和a belly builder的問題。兩句是為unusual position titles作鋪墊。第三句but表明句子重心在此，為主題句。隨后的句子進(jìn)一步闡釋a kiss mixer和a belly builder兩個專業(yè)名詞的內(nèi)涵，符合“歸納—演繹”的段落展開模式。

當(dāng)主題句在段中時，前面的句子有時不是為主題句作歸納鋪墊，而是作為對照，但其作用仍然是引出所需重點說明的話題或內(nèi)容。

例4? ?The four countries that belong to the United Kingdom work together in some areas. They use the same flag， known as the Union Jack， as well as share the same currency and military defence. However， they also have some differences. For example， England， Wales， Scotland and Northern Ireland all have their different education systems and legal systems. They also have their own traditions， like their own national days and national dishes. And they even have their own football teams for competitions like the World Cup！

【解析】前兩句講的是英屬四個區(qū)域的共同點，為下文重點需要說明的不同點作對照。第三句However引出本段著重要說明的差異性。從第四句開始往后的句子都是具體說明四個區(qū)域的差異所在。這樣看來，第三句就是主題句。

（4）演繹—歸納法

英語說明文有時會出現(xiàn)段首和段尾都有與主題相關(guān)的句子。這時，作者先用演繹法展開段落，段首提出主題思想，中間句子做具體說明，段尾再用歸納法重申主題。這樣，段落以“演繹—歸納”的方式展開，主題句在段首、尾，以首句為主。

例5? ?In the same way， many ordinary jobs may look plain， but they are necessary to society. As we go through our daily lives， we meet many different kinds of people—shopkeepers， who sell us things in shops; drivers， who drive trams and buses transporting us around the city; barbers， who cut our hair in barbershops， and cleaners， who clear up our rubbish. These jobs may not seem very attractive， but they are all important. For example， if no one was to collect the rubbish， the streets would soon become very dirty， the number of rats would increase， and disease would spread. These people， who perform such ordinary but vital tasks allow others to go about their daily lives.

【解析】段首In the same way承接上文，首句中畫線部分是主題句，揭示本段重點要闡明的主題思想。隨后的幾句列舉shopkeepers、drivers、barbers、cleaners等工作看起來似乎不那么有吸引力，但很重要。最后一句既是本段的總結(jié)，也是回應(yīng)首句的主題思想，并作進(jìn)一步重申和提高。

2.時間和空間順序

時間順序即按照事物發(fā)生、發(fā)展先后順序來說明;空間順序按照事物存在的空間形式或變化路徑來說明，如從外到內(nèi)、從上至下、由遠(yuǎn)而近等。英語說明文段落不一定按照一種順序展開，有時呈現(xiàn)出以某種順序為主的特點。

例6? ?Another unique human characteristic is that we walk upright. Standing up， its easier to find food or enemies. In addition， their arms that are unnecessary for moving around are freed for other purposes， like throwing stones or signaling. As a result， humans can perform very complex tasks with their hands.

【解析】此段以In addition，As a result短語為標(biāo)記，以時間（或程序）順序說明人直立行走過程中手臂逐步得到解放并為他用;從邏輯順序來看，本段是以演繹法展開，首句概說主題思想，即人類的另一個特點是直立行走。后面都為擴(kuò)展句，進(jìn)一步說明人直立行走以后解放了雙手用于其他目的。因此，主題句在段首。

當(dāng)說明文說明的是一件事情或現(xiàn)象的發(fā)生、發(fā)展過程，段落更多地依據(jù)時間、空間順序直敘其程序或步驟。有時，看起來都是具體的細(xì)節(jié)，但主題隱藏其中，只是沒有現(xiàn)成的概括性主題句，這就需要學(xué)生學(xué)會捕捉與主題有關(guān)的詞匯，提煉主題句。

例7? ?China opera developed from folk songs， dance， talking， antimasque and especially distinctive dialectical music. Gradually it combined music， art and literature into one performance on the stage. Accompanied by traditional musical instruments， actors present unique melodies which may sound strange to foreigners as well as beautifully written dialogues， which are of high literary value. These dialogues also promoted the development of distinct literary styles， such as Zaju in the Yuan Dynasty. For Chinese， especially older folks， listening to this kind of opera occasionally is a real pleasure.

【解析】此段以Gradually為時間順序標(biāo)記詞，輔之以動詞developed和promoted，依次說明京劇的起源、舞臺表演藝術(shù)的產(chǎn)生、獨特的文學(xué)價值和風(fēng)格以及最終成為中國民眾喜歡的一種藝術(shù)形式。此段沒有明顯的主題句。學(xué)生可以抓住與China opera有關(guān)的主題詞匯，如developed、combined、music、art、literature，提煉主題句為：Developed from and combined with different arts， China opera is of great value in music， art and literature and popular with Chinese.

（二）段落以不同的句式開頭展開說明

1.段首是疑問句

如果段首是疑問句，將問題和答案融合起來就可以提煉主題句。如果問題答案的后面出現(xiàn)but、however等轉(zhuǎn)折詞，那么，其后面的句子是重點，也常常是主題句所在。

例8? ?Does face-down generation need a heads-up？ Well， probably not. The fact is that many of todays teenagers are better educated and more creative than past generations. They also seem to be enthusiastic and willing to become leaders. More young generations than ever volunteer to help their communities. There are also brave young people such as Malala Yousafzai， the teenager who won the 2014 Nobel Peace Prize for pushing girls rights to go to school.

【解析】本段以一般疑問句開頭提出主題，后一句的答案是否定的。分析段落展開方式可知，從第三句往后的句子是擴(kuò)展句，為段首問題得到否定答案提供依據(jù)或佐證。由此，將問題和答案結(jié)合起來可提煉主題句：Face-down generation may not need a heads-up.

例9? ?Do you like to take selfies？ Its easy to take a quick picture of yourself to show what youre doing， or how youre feeling. But paying attention to ourselves often makes us feel worse. Therefore， try taking pictures of your friends. Do your best to highlight the wonderful things that make them special. In this way， you wont focus so much on your bad hair day， and you will get along better with your friends.

【解析】此段也以一般疑問句開頭，但問句后沒有直接給出答案，而是說明此問題意義不大。與例8有所不同，其后雖有but表示轉(zhuǎn)折，但作者并沒有在but后面的句子中表述主題思想，而是揭示了不理想的狀況。而Therefore后面try taking pictures of your friends才是作者真正要提出的建議。再看接下去的句子講的是給朋友拍照的好處，是對此句的擴(kuò)展與延伸。因此，主題句應(yīng)為段中的try taking pictures of your friends。

2.段首是陳述句

如果段首句是陳述句，必須分析其是否有擴(kuò)展下文的空間和余地。比如，“Exercising is beneficial”就具有主題句概括性的特征，作者可以接著闡述或列舉鍛煉的好處，如鍛煉可以增強體質(zhì)、使人形象更美等。與之相對照，“The bird has a neck”就是一個有具體意義的句子，不容易再進(jìn)一步擴(kuò)展，做主題句的可能性小。

例10? ?Lighting matters， too. When Berlin restaurant customers ate in darkness， they couldnt tell how much theyd had： those given extra-large shares ate more than everyone else， none the wiser—they didnt feel fuller， and they were just as ready for dessert.

【解析】本段以演繹法展開，以陳述句“Lighting matters”開頭，有主題句的特征，提出本段主題：燈光重要。后面句子都是在主題句之下進(jìn)行的拓展，闡述了顧客在暗淡燈光下沒有意識到吃得很多，被給了大份額食品的顧客吃得比別人多，還不覺得飽，繼續(xù)要甜點。

3.段首是祈使句

如果段首是祈使句，該句常是主題句。這在介紹用途、注意事項、建議之類的說明文中尤其多見。

例11? ?Be sociable. Participating in clubs， activities， and sports increases your chances of meeting new friends. While you only need 4 or 5 close friends， that doesnt mean you shouldnt try to meet new people. Participating gives you something to do instead of sitting bored at home and wallowing in self-pity.

【解析】這段文字以祈使句開頭作為主題句，第二句往后的句子是擴(kuò)展句，進(jìn)一步闡釋Be sociable可以怎么做以及這么做的理由。

二、主題句的轉(zhuǎn)述

一般來說，轉(zhuǎn)述常有以下三種方法：從詞或短語的角度入手，采用同義替換或詞性轉(zhuǎn)換的方法;從語法的角度轉(zhuǎn)換主被動語態(tài);從釋義（paraphrase）的角度，對主題句進(jìn)行重組和改寫。

以例1至例5中的主題句為例。

Topic sentence 1? Written Chinese has also become an important means by which Chinas present is connected with its past.（句中also是對上文意義的增補，表示遞進(jìn)關(guān)系，在概要寫作中可根據(jù)上下文需要選擇保留或省略，在此單句中暫且忽略）

轉(zhuǎn)述1? ?Written Chinese has become a significant way of connecting Chinas present and its past.（同義替換：an important means→ a significant way+語態(tài)轉(zhuǎn)換：is connected→connecting）

轉(zhuǎn)述2? ?Written Chinese has become a connection between Chinas present and its past.（詞性轉(zhuǎn)換：connected→connection+語態(tài)轉(zhuǎn)換：an important means by which Chinas present is connected with its past→ a connection between Chinas present and its past）

轉(zhuǎn)述3? ?Chinas present is linked to its past through the channel of written Chinese.（釋義）

Topic sentence 2? They have to be strong in both body and mind.（They指上文Rescue workers。在脫離上下文的情況下，主題句中使用原名詞替換代詞意思更清楚）

轉(zhuǎn)述1? ?Rescue workers must have a strong body and mind.（同義替換：have to be strong in both body and mind→ must have a strong body and mind）

轉(zhuǎn)述2? ?Rescue workers have to be strong both physically and spiritually.（詞性轉(zhuǎn)換：have a strong body and mind→be strong both physically and spiritually）

轉(zhuǎn)述3? ?Rescue workers have to be well-built both physically and spiritually.（釋義）

Topic sentence 3? There are also many unusual position titles.（在無上文的情況下此主題句看起來有點突兀?？梢园言闹凶鳛閷φ盏腗ost jobs have common titles部分信息補充到主題句中，使其完整清晰）

轉(zhuǎn)述1? ?Similarly， unusual jobs have their equivalent titles.（釋義）

轉(zhuǎn)述2? ?Like common jobs， there are lots of titles for unusual ones.（釋義）

Topic sentence 4? They also have some differences.（用The four countries替換代詞They，使主題句意思更為清楚）

轉(zhuǎn)述1? ?There are some differences between the four countries. （同義替換：have→There are）

轉(zhuǎn)述2? ?The four countries are different from one another.（詞性轉(zhuǎn)換：differences →different）

轉(zhuǎn)述3? ?The four countries have their unique education and legal systems as well as traditions.（釋義：根據(jù)主題句后面擴(kuò)展句的含義，補充信息，以使主題句意思完整清晰）

Topic sentence 5? Many ordinary jobs may look plain， but they are necessary to society.

轉(zhuǎn)述1? ?Lots of plain and ordinary jobs are essential to society.（同義替換：necessary→essential）

轉(zhuǎn)述2? ?Ordinary and plain， lots of jobs are essential to society.（釋義）

值得注意的是，主題句轉(zhuǎn)述的前提是忠實于原文。選擇什么樣的方法來轉(zhuǎn)述主題句，要根據(jù)具體內(nèi)容確定。適當(dāng)時候還需要對主題句的信息進(jìn)行補充，使意思完整清楚。

英語說明文概要寫作可以借助說明文的篇章結(jié)構(gòu)特點與段落展開方式定位與提煉主題句，從詞、句、語法以及釋義的角度轉(zhuǎn)述主題句，從而個性化地表達(dá)主旨。但提煉、轉(zhuǎn)化后的主題句還需有機銜接，以確保說明文概要行文流暢，意思完整。

參考文獻(xiàn)：

[1]杜龍芳. 英語文章段落內(nèi)部結(jié)構(gòu)研究[M]//成都翻譯協(xié)會，等.外語教育與翻譯發(fā)展創(chuàng)新研究.成都：四川師范大學(xué)電子出版社，2016：39.

[2 ]黃葦. 基于原型范疇理論的英語說明文語篇特征研究[J]. 英語教師，2019（21）：50.