(1)单破折号
单破折是用来解释说明其前面的信息的。
① Half of the world’s 6800 languages are likely to vanish within two generations—that’s one language lost every ten days. (C4T2P1)
解析：“that’s one language lost every ten days”用来解释vanish，表示的是lost，两者意思相同。
② …you can see the rough outlines of what are called tectonic plates—the plates which make up the earth’s crust and mantle. (C4T3P2)
解析：“the plates which make up the earth’s crust and mantle”用来解释“tectonic plates”，即组成地球地壳的板块。
(2)双破折号
双破折号在文章中经常出现，它用来解释说明第一个破折号前面的信息，当这个信息是以生词的形式表现出来的话，有了破折号也就不难理解了。再者，双破折号的信息去掉，也不会影响句子的整体意思。
① Sometimes it is slow: vast bubbles of magma—molten rock from the mantle—inch towards the surface, cooling slowly… . (C4T3P2)
解析：“molten rock from the mantle”用来解释“vast bubbles of magma”，即“地壳中的熔岩”。
② For the so-called power events—that require a relatively brief, explosive release of energy, like the 100-metre sprint and the long jump—times and distances have improved ten to twenty percent. (C4T4P1)
解析：“that require a relatively brief, explosive release of energy, like the 100-metre sprint and the long jump”用来解释“power events”，即“力量型赛事”。
2、插入语的双逗号
句子中经常会出现插入语，即前后用逗号与整个句子结构分开的短语，句子结构，这个成份如果是做同位语成分的名词短语或者非限定性定语从句，通常是用来解释第一个逗号前面的信息的。
Passive smoking, the breathing in of the side-stream smoke from the burning of tobacco between puffs or of the smoke exhaled by a smoker, also causes a serious health risk. (C3T1P2)
解析：如果学员不认识“passive smoking”，逗号后有解释，即“吸入抽烟者吞吐烟草燃烧的烟雾”。
3、分号
分号用来连接前后两个句子，相当于适当的“逗号+并列练习and，but或or+句子”。词汇猜测时，利用的是分号前后两个句子之间的逻辑关系是列举、转折还是选择。
Some corpora attempt to cover the language as a whole, taking extracts from many kinds of text; others are extremely selective, providing a collection of material that deals with only a particular linguistic feature. (C4T3P3)
解析：根据前后之间的语境，判断出“extremely selective”即指“不全面的，只是包含一部分的”。
4、冒号
冒号在英语句子中也是起到解释说明冒号前面信息的作用。
Typically, children do not end up on the streets due to a single reason, but to a combination of factors: a dearth of adequately funded schools, the demand for income at home, family breakdown and violence. (C4T3P1)
解析：根据前后之间的并列关系，可以推测dearth是名词，且是贬义，相当于lack、shortage、inadequacy、deficiency。
