在宾语从句中，当主句的谓语动词为think,believe,expect,imagine,suppose等时，如果主句为I或we时，从句中表示否定意义的not应移到think,believe,expect,imagine,suppose等前。如：
形式上否定主句的谓语，实际上是否定从句的谓语。
当动词think, believe, suppose, imagine, expect, feel的主语是第一人称、谓语动词为没有任何副词修饰的一般现在时，它们的否定式实际上是对宾语从句的否定。表示说话者提出一种委婉的看法或主张。如：
I think that he will help us. —I don't think that he will help us. 我认为它不会帮助我们。
I believe that he is right. —I don't believe that he is right. 我认为他不对。
I suppose that he likes it. —I don't suppose that he likes it. 我想他不喜欢它。
2. 形式上否定谓语动词，实际上否定复合宾语。
当动词think, believe, suppose, imagine, expect, feel, find的主语是第一人称、谓语动词为没有任何副词修饰的一般现在时，它们前面的否定式实际上是对复合宾语的否定。表示说话者所提出的一种委婉的看法或主张。如：
I think math difficult. — I don't think math difficult. 我认为数学不难。
I find the story interesting. — I don't find the story interesting. 我认为这个故事没有趣。
I expect so. —I don’t expect so. 我认为不会。