能給你的文章加分的英文分號(hào)與圓括號(hào)用法

分 號(hào)

分號(hào) (semicolon)?可以認(rèn)為是介于句號(hào) (period)?和逗號(hào) (comma)?之間的一種標(biāo)點(diǎn)。它與句號(hào)的相同之處在于，兩者都是用來(lái)分隔兩個(gè)完整的句子——換句話說(shuō)，分號(hào)前后的句子在語(yǔ)法上都應(yīng)該是獨(dú)立完整的，中間不需要連詞，這一點(diǎn)與逗號(hào)不同。而它與句號(hào)的區(qū)別則在于，在文氣和邏輯上，分號(hào)并不像句號(hào)那樣有很強(qiáng)的分隔作用，這一點(diǎn)則于逗號(hào)接近。試對(duì)比下面三個(gè)句子：

Noble metals generally exhibit excellent catalytic performances, however, their applications are limited by the relatively low abundance and high cost.???

Noble metals generally exhibit excellent catalytic performances. However, their applications are limited by the relatively low abundance and high cost.???

Noble metals generally exhibit excellent catalytic performances; however, their applications are limited by the relatively low abundance and high cost.????

例句1中，兩個(gè)句子以逗號(hào)分隔開，兩句之間在邏輯上是轉(zhuǎn)折關(guān)系，但中間缺少連詞（注意，however是副詞而不是連詞），所以在語(yǔ)法上是錯(cuò)誤的。

例句2中，兩個(gè)句子以句號(hào)分隔開，所以在語(yǔ)法上并無(wú)不妥 (grammatically correct) 。但從兩句之間的邏輯關(guān)系上來(lái)看，則顯得有些斷裂，即文氣不暢。另外從英文中多長(zhǎng)句這一習(xí)慣來(lái)看，兩句之間用句號(hào)斷開也顯得有些碎片化。

例句3中，兩個(gè)句子以分號(hào)分隔開，既不像逗號(hào)一樣需要連詞，也不像句號(hào)一樣將文氣截?cái)唷獡Q句話說(shuō)，既保證了語(yǔ)法上的正確性?(grammatical correctness)?，又保證兩個(gè)句子在邏輯上的連貫性?(logical continuity) ；同時(shí)兩句連綴成一個(gè)長(zhǎng)句，也符合英文的表達(dá)習(xí)慣。

簡(jiǎn)而言之，從語(yǔ)法上來(lái)說(shuō)，任何一個(gè)分號(hào)都可以替換成句號(hào)；但從文氣上來(lái)講，分號(hào)更突顯前后兩句在邏輯上的「藕斷絲連」。下面按各種邏輯關(guān)系各舉幾例：

1. 并列關(guān)系（常與冒號(hào)配合使用）：

Matter can undergo two types of changes: chemical changes or reactions are changes in composition;?physical changes are changes in state or physical form and do not affect composition.

The four basic stages of the scientific method are: (1) XXX; (2) XXX; (3) XXX; (4) XXX.

2. 轉(zhuǎn)折關(guān)系：

All truths are easy to understand once they are discovered; the point is to discover them.

Gamma ray is not made up of particles;?rather it is electromagnetic radiation of extremely high penetrating power.

3. 遞進(jìn)關(guān)系：

Astronomy's tools are not only diverse; they are also changing rapidly.

As designed, both space probes sent by NASA will not only detect Earth-like planets around nearby stars; they will also measure the planets’ physical and chemical characteristics.

4. 因果關(guān)系：

When a static positive charge builds up in one place, a negative charge of equal size appears somewhere else;?therefore, charge is balanced.

The outer planets move slowly and their orbits are very large;?thus they take a long time to go once around their orbit.

5. 對(duì)比關(guān)系：

Objects at rest stay at rest;?objects in motion stay in motion.

An ordinary microscope uses a beam of light to illuminate the object;?an electron microscope uses a beam of electrons.

6. 承接關(guān)系：

In the word photon, phot-?means light;?-on?signifies a particle.

Formic acid is injected by an ant when it bites;?this leads to the burning sensation that accompanies the bite.

7. 進(jìn)一步釋義：

Mass and volume are extensive properties;?they depend on the amount of matter in a sample.

The properties of nonmetals are generally opposite those of metals;?for example, nonmetals are poor conductors of heat and electricity.

另外，如果分號(hào)隔開的句子之間在結(jié)構(gòu)上相似，在用詞上重復(fù)，則可以將重復(fù)的部分適當(dāng)省略，用逗號(hào)代替，這樣可以減少啰嗦冗余之感。試比較：

By 1994, astronomers had found only three exoplanets; by 2017, they had found about 3500.

By 1994, astronomers had found only three exoplanets; by 2017, about 3500.

Some telescopes are on mountaintops; others are in Earth orbit; yet others are in interplanetary space.

Some telescopes are on mountaintops; others, in Earth orbit; yet others, in interplanetary space.

由此可見，分號(hào)間隔的句子中將重復(fù)的內(nèi)容 (紅色部分) 替換成逗號(hào)，可以讓語(yǔ)句變得簡(jiǎn)潔緊湊。

圓 括 號(hào)

圓括號(hào) (parentheses) 的作用是增加一些補(bǔ)充說(shuō)明的信息，圓括號(hào)中的內(nèi)容可能是一個(gè)單詞（甚至一個(gè)前綴/后綴），一個(gè)短語(yǔ)，或一個(gè)或幾個(gè)句子。

However, the conclusion was based on some (over)simplified assumptions. I would like to suggest?the authors?add some?(semi)quantitative?analysis results.

An oscillating (and therefore accelerating) electric charge causes a disturbance that moves outward through space as an electromagnetic wave.

Sirius, the brightest star in the sky, lies within the boundaries of the constellation Canis Major (meaning the “big dog”).

Nearly all short-period comets have prograde orbits; that is, they orbit the Sun in the same direction as the planets. (Comet Halley, with its retrograde orbit, is an exception.)

注意：圓括號(hào)中的內(nèi)容必須在語(yǔ)法上是可有可無(wú)的。換句話說(shuō)，如果把括號(hào)中的內(nèi)容去掉，原句在語(yǔ)法上必須仍是正確的。試辨析：

The Sun (and its associated planets)?are located about halfway out from the center of the Milky Way Galaxy.???【主謂不一致】

The Sun (and its associated planets)?is located about halfway out from the center of the Milky Way Galaxy.??

The Sun and its associated planets?are located about halfway out from the center of the Milky Way Galaxy.??

科技論文要求論述嚴(yán)謹(jǐn)，而圓括號(hào)可以起到「打補(bǔ)丁」的作用，減少語(yǔ)義上的漏洞，讓表意更加精準(zhǔn)且豐富。例如：

Salts of Group 1 cations (with some exceptions for Li+) are soluble.

For most materials (water ice being a rare exception), the solid form of the material is more compact than the liquid form.

With the speed of light, it will take us a bit over four years to cover the distance from Earth to the nearest star?(other than the Sun).

The European Union has funded two specific?flagship efforts, one in graphene (and other two-dimensional materials),?and the Human Brain Project, which seeks to simulate the human brain.

當(dāng)然，引入補(bǔ)充說(shuō)明的成分還可以借助逗號(hào) (comma)或長(zhǎng)劃線 (em dash)，但相比之下，圓括號(hào)的優(yōu)點(diǎn)在于可以讓語(yǔ)句顯得更加緊湊、有層次而不至于瑣碎或喧賓奪主，有時(shí)還可以起到消除歧義的作用。試看下面幾例：

For more challenging reactions (such as toluene oxidation), no catalysts capable of high-efficiency and large-scale conversion have been reported.【此處若用逗號(hào)，會(huì)顯得有些碎片化】

Because the electric field points directly away from a positively charged particle (or directly toward a negatively charged particle), the force that a second charge feels is either directly toward or directly away from the first charged particle.【此處的圓括號(hào)使前半句更加緊湊，且降低了前半句的份量感；如果橙色部分不放到圓括號(hào)里，前半句會(huì)顯得有些啰嗦笨重，讓整個(gè)句子有「頭重腳輕」之感】

Human-made space probes have landed on Mars, Venus, Titan (Saturn’s largest moon), and an asteroid.【此處橙色部分為注釋說(shuō)明成分，圓括號(hào)可使層次更加分明；若將圓括號(hào)改為逗號(hào)，則會(huì)產(chǎn)生歧義】

多說(shuō)一句，在一些不太嚴(yán)肅的語(yǔ)境中，圓括號(hào)還很適合用來(lái)吐槽，提升幽默感。試體會(huì)：

Long before Columbus’s famous (or possibly infamous) journey to the New World, anyone who had read Aristotle or other Greek philosophers knew that Earth is a ball.【括號(hào)里的內(nèi)容說(shuō)明，哥倫布發(fā)現(xiàn)新大陸之旅是舉世聞名的，但在某種意義上也是臭名遠(yuǎn)揚(yáng)的】

After three weeks on set, the cast was fed up with his direction (or, rather, lack of direction).【括號(hào)里的內(nèi)容說(shuō)明，演員們都受夠了導(dǎo)演低水平的導(dǎo)戲，甚至認(rèn)為那都不能叫「導(dǎo)戲」】