并列句(compound sentence)指的是由两个或两个以上的
简单句并列在一起构成的句子。并列句的通常结构是：简单句+
并列连词+简单句。其中的简单句通常被叫做分句。并列连词之前可用逗号，也可不用逗号。
如：由and ,not only ...but also ,neither ...nor ,then ,or ,either ...or ,otherwise,but ,still,however.yet ,while,so ,for ,therefore...连接的句子,基本结构是：分句+ 连词+ 分句
例如：■He drank beer, and it made him fat. 他喝啤酒，因此发胖了。(并列连词是and)
■He was ill for a week, and during that week he ate nothing. 他病了一星期，在那一星期里他什么也没吃。(并列连词是and)
■Stephen realized his mistake and he apologized at once.
斯蒂芬认识了他的错误，于是马上道歉。(并列连词是and)
■Stop the child or he will be falling over. 制止那孩子，要不他会掉下去。(并列连词是or)
■He speaks French, or perhaps he understands it. 他会讲法语。或者他懂法语。(并列连词是or)