连词：that(that 常可省略)whether, if
代词：who, whose, what ,which
副词：when ,where, how, why 等。
say, think, insist, wish, hope, demand, imagine, wonder, know, suppose, see, believe, agree, admit, deny, expect, explain, order, command, feel, dream, suggest, hear, mean, notice, prefer, request, require, propose, declare, report等。
例句：The boy believes that he will travel through space to other planets.
注意事项：当主句谓语动词是 think, believe, suppose, expect 等词，而宾语从句的意思是否定时，常把否定转移至主句表示。
例句：I don't think it is right for him to treat you like that.
例句：He said (that) you were too young to understand the matter and that he was asked not to tell you.
例句：Just then I noticed, for the first time, that our master was wearing his fine green coat and his black silk cap.
例句：I can't tell him that his mother died.
例句：I find it necessary that we should do the homework on time.