◆ Wrong: Earl walked to school, AND later ate his lunch.
◆ Right: Earl walked to school AND later ate his lunch.
◆ Right: Earl walked to school, AND HE later ate his lunch.
◆ Right: The dam has created dead zones, WHERE fish have disappeared.
◆ Wrong: The dam has created dead zones; fish have disappeared.
分号又常常同些连接副词一起使用，如however, therefore, or in addition ，注意这些词和连词and 等又完全不相同，所以对于这些词，常常使用分号进行连接：
◆ Wrong: Andrew and Lisa are inseparable, THEREFORE, we never see themb apart.
◆ Right: Andrew and Lisa are inseparable; THEREFORE, we never see them apart.
◆ Wrong: I listen to Earth, Wind & Fire, Wow, Owls, and Blood, Sweat & Tears.
◆ Right: I listen to Earth, Wind & Fire; Wow, Owls; and Blood, Sweat & Tears.
冒号(:)为之前的事提供进一步的解释，说明。冒号前的通常是一个句子，可以独立存在，而冒号后则无需是句子，而有时会在冒号后加入namely 或that is。
I love listening to many kinds of music:
namely, classical, rock, rap, and pop.
◆ Worse: Three factors affect the rate of a reaction: concentration, surface area, and temperature.
◆ Better: The rate of a reaction is affected by three factors: concentration, surface area, and temperature.
破折号( - )是一个灵活的标点符号，GMAT考试中偶尔会用到。有时破折号可以代替逗号来使用：
By January 2, 2000, the so-called “Y2K problem” was already widely considered a joke—although the reason for the non-event was the huge corporate and governmental investment in prior countermeasures.
My three best friends—Danny, Jimmy, and Joey—and I went skiing.
这句话如果用逗号就会让人误以为有七个人go skiing 。破折号有时用来解释或重复之前句子的某个部分，但不像冒号需要紧跟着需要解释的词前面：
Post-MBA compensation for investment bankers tends to surge far ahead of that for management consultants—by tens, if not hundreds, of thousands of dollars a year.
上面的这个例子中by tens, if not hundreds, of thousands of
dollars a year 解释句子前面的far。
In 1988, the Council on Economic Priorities began publishing Shopping for a Better World, with the simple thesis of consumers having the power to change companies by the simple expedient of refusing to buy.
A. with the simple thesis of consumers having
B. which had the simple thesis of consumers having
C. where the thesis was simple: consumers having
D. with a thesis that is a simple one: consumers have
E. whose thesis was simple: consumers have
题目释义：the Council began publishing SFBW, whose thesis was simple：consumers have…
A. 用with引导的非限定性短语做伴随状语错误，而事实上，thesis是Shopping for a Better World这本书的主题，不能作为前面整句话的伴随；thesis后面用of不好，thesis变成了某一类特定的consumers，而合理含义上应该是一个thesis应该是某个现象，因此要改为that从句(同位语从句)，或者用冒号来引出从句。
B. Thesis应该用同位语从句修饰；thesis of sb. doing sth.累赘，结构含糊。
C. 关系代词where指向Shopping for a Better World不恰当；冒号后面要用完整句子，缺少谓语。
D. with的错误同A，后面a thesis that is a simple one不简洁。