并列连词
(1)表示转折的并列连词常见的表示转折的并列连词有while，but，yet，however，nevertheless，still等，用来连接两个意思不同甚至相反的词、短语或分句I was born in Xian while I grew up in Changchun．我出生在西安，然而在长春长大。He wants to go, but his sister wants to stay.他想走，但他妹妹想留下。The problem is difficult, however, many of us have solved it．这道题目是难了些，但我们很多人都做出来了。
(2)表示因果的并列连词常见的表示因果的并列连词有：so，for，hence，thereforeThe boss called me just now, so I must go to the office at once.老板刚才打电话找我，因此我必须马上去办公室。I must be away for a week, for III fix the machine for a factory.我必须离开一周，因为要为某厂修机器。注意：副词then（那么，因而），thus（因此），therefore ( 因此．所以 ) 等也可以放在句首表示因果关系He studied hard, then he got a full mark.他很用功，因而他得了满分。His car broke down, thus he was late for work.他的车坏了，因此他上班迟到了。He was busy, therefore he could not come.他很忙，因此他没有来。
(3)表示选择的并列连词常见的表示选择的并列连词有：oror else（否则）either…or…otherwise（要不然；否则）
or 的用法
a．or 意为“或”表示一种选择Would you like tea or coffee？你想喝茶还是咖啡？b．or用在“祈使句+or +简单句”结构中，其中or在此意为“否则”Study hard, or you will fail.努力学习，否则你就会失败。c．or用在否定句中代替and表示并列关系He can read or write.他既不会读也不会写。You must be joking,or elseyou e mad.你一定是开玩笑，不然你就是疯了。You may wear either of the coats.你可以穿两件大衣中的任何一件。Either you or he has to go.=Either he or you have to go．不是你就是他得去。（就近原则）He reminded me of what I should otherwise have forgotten．他提醒了我，要不然我就会把这件事给忘了。
(4)表示并列关系的连词常见的表示并列关系的并列连词有：andnot only…but also…as well asboth…and…neither…nor…either…or…它们用来连接两个并列或对称关系的词、短语或分句Kate and I are in the same class.凯特和我在同一个班。We should not only be cautious but alsobe brave.找们不仅应该谨慎而且应该勇敢。She is a writer as well as a teacher.她既是一个作家又是一位教师。Both you and she are right．你和她都对。Neither you nor I am to blame.你和我都不应受责备。Come to see her either today or tomorrow.今天或明天来看她吧。
