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(名词性从句、定语从句和状语从句)。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.