名词doubt后面接同位语从句 (1)doubt用在肯定句中,后面接whether引导的同位语从句。注意不可以用if替换whether。例如: He had his doubts whether they would give him another chance to have a try. 他不能肯定他们是否会再给他一次机会试一试。 (2) doubt用在否定句中,后面接that引导的同位语从句。 例如: I have no doubt that he will succeed. 我相信他会成功的。 动词doubt+宾语从句 (1) 在否定句和疑问句中,doubt后面接that引导的宾语从句。 例如: I don”t doubt that he can finish the task on time. 我相信他能按时完成任务。 Do you doubt that she will succeed? 你怀疑她会成功吗? (2) 在肯定句中,doubt后面一般接whether或if引导的宾语从句。 例如: I doubt whether they can swim across the river. 我怀疑他们能否游过河去。 He doubts if she will keep her word. 他不敢肯定她是否会遵守诺言。