（1）连接词and连接两个名词。
汤姆和杰瑞将去美国。
（2）连接词and连接两个动词片语。
他们锁上门就去睡觉了。
（3）连接词for连接两个对等子句。
因为没有足够的钱,他没和我们一起去。
从结构上说，英语连接词分两大类：并列连词（coordinating conjunctions）和从属连词（subordinating conjunctions）。
并列连词连接两个或两个以上地位平等的字、词组或分句。例如：
(1) Air and water are indispensable to me.
(2) She likes going out with friends or playing outdoor games.
(3) Most workers have a good income, so they look very happy.
从属连词连接两个或两个以上的分句，形成复杂句中的从属分句。例如：
(4) He said that he did not want to go .
(5) Many things have happened since I last saw him.
(6) You may come if you want to.
上述连词的用法，看起来不难，但错误也难免。下面是些好例子：
(1) This book may be used both as a text as well as a reference book.
这里的“as well as”和“both”不能搭配，应该将“as well ”改为“and”，使“both.......and......”变成关联连词（ correlative conjunction）
(2) He not only speaks Mandarin but also English.
这里的“not only”应该移到“speaks”后面，使这个动词兼顾两个等立宾语：“Mandarin”和“English”。
(3) Although he is fat, but he is very weak.
英语里的“although”和“but”是不见面的 ，因此这句里的“ but”要去掉，不然“although”就要出来。
(4) Jim is not so strong like you.
这里的“not so”必须和“as”连成一体；介词“like”是不适宜的。
(5) No sooner had we reached our destination, they left.