電力科技英語閱讀中的主謂結構分析
莊起敏
【摘 要】電力科技英語文獻中常常含有結構復雜的長句,要理解這些長句的關鍵往往在于正確地把握句子的主謂結構。從英語名詞的數、英語主謂結構基本類型、定語從句主謂結構等方面入手,可以較好地掌握英語主謂結構分析的方法,從而提高電力科技英語閱讀理解的能力。
【關鍵詞】電力科技英語;名詞的數;主謂結構分析
1.引 言
一般來說,英語的主謂結構與漢語相同:主語在前,謂語在后。但是,由于英語名詞有單復數的變化,加上英語中作主語的名詞和與作謂語的動詞之間常常可以插入定語和狀語,有時,這些定語或狀語由較長的從句擔任;再有英語中還有倒裝結構,作主語的名詞放到了作謂語的動詞之后;這一切都為正確找出主句的主謂結構帶來了困難。請看下面3句選自電力科技英語文獻的句子:
[1] The 20th century has witnessed a big expansion of electrical power generation and distribution. The general pattern has been toward ever-larger units of production, using steam from coal- or oil-fired boilers. Economies of scale and the greater physical efficiency achieved as higher steam temperatures and pressures were attained both reinforced this tendency.
[2] Among the more common reasons why certain generators are necessary for reliable system operations are the need to maintain adequate voltages, reactive power requirements, reserve requirements, and unit commitment requirements.
[3] In recent years many discoveries have been made in this field which greatly faciliate the study of electricity and gives a new conception of the nature of matter.
在句[1]中,斜體部分句子的主語是Economies of scale and the greater physical efficiency。但謂語何在?句[2]中的兩個are,哪一個是謂語動詞,主語又在哪里?句[3]中斜體部分的which是定語從句的主語,但它指代什么?這3個實例表明:電力科技英語文獻中句子的主謂結構必須認真分析才能真正弄清,從而為正確理解句子奠定基礎。
下面從英語名詞的數、基本的英語主謂結構類型、定語從句的主謂結構判別等方面討論英語主謂結構的分析方法。
2.英語名詞的數
英語句子的主語主要由名詞和代詞來擔任,代詞相對而言較為簡單,而英語的名詞與漢語不同,在形式上有數的變化,即在詞尾加上-s表示復數;同時,謂語動詞根據主語的單復數也發生相應的單復數的變化。這一方面使語言變得復雜,但另一方面也為我們正確識別主謂結構提供了依據,例如:
[4] The expanding gas coming from the turbine and movng along the jet nozzles continues to expand and accelerate to form a high velocity.
句中謂語動詞continues加上了-s,提示主語一定是單數,所以它的主語不可能是前面的the jet nozzles,而是the expanding gas。
在英語語法中,有關名詞的數的內容很多,但從幫助分析英語主謂結構的目的出發,主要應該掌握下列要點。
2.1.-s結尾的名詞不一定是復數
在英語中,部分以-s結尾的名詞需要動詞以單數形式與其保持一致,主要有:
(1)表示學科含義的詞,例如:
[5] Electronics(電子學)is the basis of all communications system.
[6] Thermodynamics(熱力學)deals with the relationship between heat and other forms of energy.
又如:mechanics(力學)acoustics(聲學),informatics(情報學,信息學),mathematics(數學),optics(光學),physics(物理學),plastics(塑料學)等等。
(2)表示疾病名詞的詞,例如:
[7] Diabetes(糖尿病)is a common disease.
[8] Generally measles(麻疹)occurs in children.
又如:arthritis(關節炎),shingles(帶狀皰疹)等等。
(3)某些專有名詞,例如:
[9] General Motors (通用汽車公司)produces many different types of cars.
[10] The United States(美國)exports a lot each year.
又如:the United Nations(聯合國),the New York Times(紐約時報)等等。
2.2.-s結尾的單詞可以是單數,也可以是復數
在英語中也有相當一部分以-s結尾的名詞,在一定的上下文中,既可以是單數,也可以是復數,例如:
[11] A series of accidents(一系列事故—)has been reported in that power plant.
[12] There are two series of transformers(兩種系列的變壓器)used in this project。
[13] Is this the only means (唯一的方法)to produce electricity in this area?
[14] There are various means(各種方法)of increasing our power production.
又如:steel-works(鋼鐵基地),species(物種),headquarters(指揮部)等等。
一般來說,確定這種名詞的單復數,主要看它們前面有關數量的修飾詞,a,the only等提示作單數用,two,various提示作復數用。
2.3.不是以-s結尾的名詞也可以是復數
如前所述,-s結尾的名詞不一定是復數;同樣道理,不是以-s結尾的名詞也不一定全是單數。英語中部分非-s結尾的名詞要作為復數使用,例如:
[15] The committee(委員會)are pided in their opinion about the construction of a nuclear power station in that densely-populated area.
[16] Do vermin(害蟲)do harm to electrical installations?
又如:police(警察),cattle(牲口),staff(員工)等等。
2.4.單位詞、百分數、分數等的使用
有時,名詞需要與單位詞、百分數或者分數一起使用,這時謂語動詞的單復數就需要發生相應的變化。一般來說,可以遵循下列句型:
單數單位詞 + of + 名詞:單數謂語動詞
復數單位詞 + of + 名詞:復數謂語動詞
百分數/分數 + of + 可數名詞復數:復數謂語動詞
百分數/分數 + of + 不可數名詞:單數謂語動詞
例如:
[17] A large piece of land is marked out for the construction of a coal field.
[18] Three boats of coal are needed.
[19] Only 25 % of the capital is American-owned
[20] One-fifth of the generators are being repaired.
3.基本的英語主謂結構類型
從便于識別與閱讀的角度看,可以將英語中由名詞充當主語的主謂結構分為下面幾種類型:
單個名詞 + 謂語動詞
單個名詞 + 后置定語/狀語 + 謂語動詞
(3) 并列名詞 + 謂語動詞
(4) 并列名詞 + 后置定語/狀語 + 謂語動詞
(5)謂語動詞 + 名詞
另外,還有下列由非謂語動詞或從句充當主語的類型:
(6)不定式(短語)+ 謂語動詞
(7)動名詞(短語)+ 謂語動詞
(8)主語從句 + 謂語動詞
單個名詞 + 謂語動詞
單個名詞作主語是最簡單的主謂結構,只要注意做主語的名詞本身的單復數就可以了,例如:
[21] The 20th century has witnessed a big expansion of electrical power generation and distribution.
[22] The small direct-current generators were abandoned in favour of alternating-current systems.
并列名詞 + 謂語動詞
從句子含義的角度出發,這里所指的并列名詞有三類:一是指由and、or等單個并列連接詞連接起來作主語的名詞,第二類指由not only… but also,neither… nor,either… or等組合并列連接詞連接起來作主語的名詞,第三類是指由as well as,along with,together with,in addition to,instead of等短語介詞連接起來的名詞,確切地說,第三類在結構上并不是并列關系,但由于在含義上有并列的意思,在結構上與并列結構也極為相似,所以歸在這里一起討論。
對于第一類并列主語,用and連接起來的主語,謂語動詞一般用復數。
[23] The rotor shaft and the field structure are made of a solid alloy steel forging in which slots are machined to accept the field coils, as shown in Figure 2.
用or連接起來的主語,謂語動詞的單復數由or后的名詞單復數決定。
[24] A large unit or several small units are needed.
[25] Several small units or a large unit is needed.
對于第二類并列主語,謂語動詞均與組合并列連接詞后面的一個主語在數上保持一致。
[26] Not only coal and oil but also falling water is being used to produce electricity.
[27] Either falling water or coal and oil are being used to produce electricity.
[28] Neither I nor he likes to work there.
對于第三類并列主語,謂語動詞的單復數根據as well as等短語介詞前的名詞的單復數而定。
[29] The machine as well as its auxiliary devices is imported.
[30] All the pipes along with the boiler need to be checked.
3.3 名詞 + 后置定語/狀語 + 謂語動詞
名詞加上后置定語,或者在主語與謂語之間插入狀語,句子會變得復雜一些。一般來說:主語的后置定語常由介詞短語、不定式短語、分詞短語、定語從句來充當;狀語則往往需要用逗號撇開。例如:
[31] The various manifestations of electricity are the result of the accumulation or motion of numbers of electrons.
介詞短語of electricity作主語manifestations的后置定語。一方面,manifestations與are在數上保持一致,另一方面,也提示它們之間存在主謂關系。
[32] The hydroelectric power using a fall of water to drive water turbines has been developed to generate electricity where the climate and topography make it possible to combine production with convenient transmission to a market.
分詞短語using a fall of water to drive water turbines放在主語the hydroelectric power與謂語動詞has been developed之間作后置定語。
[33] Another important factor to be taken into consideration is that current strength is equal at certain points in a series circuit.
不定式短語to be taken into consideration插在主語another important factor與謂語動詞is之間作后置定語。
[34] The electric current which we are talking about is simply a flow of electrons.
which we are talking about是句子主語the electric current的后置定語。
[55] Such magnetism, because it is electrically produced, is called electromagnetism.
原因狀語從句because it is electrically produced插在主語與謂語動詞之間。
[36] Atoms, small as they are, are made up of still smaller units known as “subatomic participles”.
主語atoms與謂語動詞are made up of之間的small as they are是一個讓步狀語從句。
一般來說,由于定語從句和狀語從句有連接詞在句首,比較容易識別,因此被它們分隔開的主語與謂語動詞也比較好找,如[34],[35]和[36]。而插在主語與謂語動詞之間的介詞短語、分詞短語和不定式短語,則需要認真分析句子成分才能加以識別,如[31],[32]和[33]。有時,主語與謂語動詞之間的后置定語不止一個,這就使句子變得更為復雜,主謂之間關系的分析需要更加仔細,例如:
[37] The communication of digital data among computers connected by wire, microwave, and satellite circuits is now a major enterprise that has built a strong bond between computer and communications specialists.
句子主語the communication與謂語動詞is之間插進了帶有過去分詞短語connected by wire, microwave, and satellite circuits的介詞短語of digital data among computers。
3.4.謂語動詞 + 名詞
這一類型是倒裝句,there be句型也在此列。例如:
[38] From these simple concepts has developed a sophisticated technique that many of the electrical companies have now adopted to make the power industry less vulnerable to the limited sources of energy.
介詞短語from these simple concepts為首,是倒裝句,謂語動詞是has developed,提示句子主語是單數,即后面的a sophisticated technique。
[39] There are four ways for transmitting power from the electric motor to the spindle.
There are是謂語動詞,are提示主語是后面的復數名詞ways。
3. 5. 不定式(短語)+ 謂語動詞
不定式短語作主語看作單數,在分析謂語動詞的單復數時,注意不要受不定式自己賓語的干擾,例如:
[40] To use any of these fuels needs our serious consideration.
主語是不定式短語,而不是fuels。
[41] To transmit electromagnetic waves takes energy.
當然,兩個或兩個以上不定式短語并列作主語,謂語動詞用復數形式:
[42] To use any of these fuels and to reuse this boiler both need our serious consideration.
3. 6. 動名詞(短語)+ 謂語動詞
與不定式短語作主語一樣,動名詞短語作主語也看作單數,在分析謂語動詞時,也要注意不要受動名詞自己的賓語的干擾;并列的動名詞短語作主語,謂語動詞也要用復數形式,例如:
[43] Using any of these fuels has an effect on the environment, as these videos show, but all of these effects can be minimized so that these fuels can continue to be used.
句子主語是using any of these fuels,謂語動詞是has。
[44] Generating current at a lower frequency and then boosting it to a higher frequency are more efficient.
句子主語是兩個并列的動名詞短語:generating current at a lower frequency和then boosting it to a higher frequency。
3.7.主語從句+謂語動詞
主語從句作主語一般看作單數,并列的主語從句一般應該用復數謂語。例如:
[45] Whether this unit will operate efficiently remains to be seen.
[46] What potential energy and kinetic energy means and how we explain these two terms have been mentioned in this article.
主語為兩個分別由what和how引導的主語從句,所以謂語動詞用復數形式have;反過來也可以這樣認為:正因為謂語動詞是復數,所以一定有兩個或兩個以上的主語。
4.定語從句的主謂結構的判別
由于定語從句的主語可能是由that或which等連接詞來充當,that或which到底指代什么,有時需要通過主謂結構的分析才能搞清,例如:
[47] This process enhances the overall thermal efficiency of energy conversion to about 50 percent--as opposed to conventional processes, which have an efficiency of about 36 to 38 percent.
定語從句的謂語動詞是have,提示連接詞which指代復數名詞,即processes。
[48] The lines of high-voltage transmission systems are usually composed of wires of copper, aluminum, or copper-clad or aluminum-clad steel, which are suspended from tall latticework towers of steel by strings of porcelain insulators.
定語從句的謂語動詞是are,提示連接詞which指代的也是復數名詞,而不是前面的steel,仔細分析可以發現:which指代復數名詞wires。
5. 結束語
現在回過頭來讓我們用上述方法分析一下“引言”部分的三個例句。在句[1]中,主語比較容易確定,是Economies of scale and the greater physical efficiency。但識別主謂結構的關鍵是找謂語動詞。從例句中可以找到achieved,were attained和reinforced三個動詞。由于achieve是及物動詞,后接as …,沒有賓語,顯然不是謂語,只是過去分詞做 efficiency的后置定語;as是連接詞,后接從句,因此,were attained是as從句的謂語;由此可見:主句的謂語應該是reinforced,both提示主語有兩個,即:Economies of scale and the greater physical efficiency。這是基本主謂結構類型3。在句[2]中,介詞短語開頭,是一個倒裝句。由于謂語是are,提示主語是復數,即后面的the need和unit commitment requirements。這是基本主謂結構類型4。句[3]是個牽涉到定語從句主謂結構判斷的句子。Which引導的定語從句中,which作主語,這是很清楚的,但which指什么?通過定語從句主謂結構的分析,可以幫助我們理解which所指。由于which引導的定語從句的謂語動詞是ficiliate,沒有加-s,指示which代表復數名詞,朝句子前面部分看,可以確定which指代復數名詞discoveries,而不是緊靠在它前面的field。
綜上所述,從英語名詞的數、基本的英語主謂結構類型、定語從句的主謂結構判別等方面入手,可以較好地把握英語句子主謂結構的分析,從而提高電力科技英語文獻的閱讀能力。
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