（2） 一般疑问句作宾语从句时，其结构为whether / if ＋陈述句。原一般疑问句的主语前如果是助动词do / does / did，应去掉，谓语动词应改为其相应的形式；原一般疑问句的主语前如果是don t / doesn t / didn t，则直接将其放到主语之后；原一般疑问句的主语前如果是be 动词、情态动词或其他助动词，则应将其放到主语之后。如：
Does he like apples? I don t know. ----- I don t know whether he likes apples.
He asks: Is Tom a diver? ----- He asks whether Tom is a driver.
（3） 特殊疑问句作宾语从句时， 如果疑问词作主语或主语的定语，其语序不用变化；如果疑问词充当其他句子成分，则宾语从句的结构为连接代词 / 连接副词＋陈述句。如：
Who can answer the question? I want to know. ----- I want to know who can answer the question.
Whose book is on the desk? We all know. ----- We all know whose book is on the desk.
When will they arrive? Please tell us. ----- Please tell us when they will arrive.
