◆ 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。