直接引语如果是疑问句,变成间接引语后,叫做间接疑问句（Indirect Questions ）。
1. 间接一般疑问句的疑问部分主语和动词不需要倒装.另外,疑问部分由if 或whether与主句连接,如:
直接一般疑问句:Is it raining ？
间接一般疑问句:He asked if (whether) it was raining.
注意: whether 可与or not 连用,表示一种选择.而if 则不可.如:
He wants to know whether or not we want dinner.
2. 间接特殊疑问句
间接特殊疑问句由特殊疑问词将主语与问句连接起来. 如:
(a) 直接特殊疑问句: Why do you come so late ？
间接特殊疑问句:Mary wanted to know why she came so late.
(b) 直接特殊疑问句:Where are going ？
间接特殊疑问句:He asked me where I was going.
注意: 当疑问词做主语时,间接疑问句的语序不变,如:
(a) 直接疑问句:Who did you see yesterday ？
间接疑问句:Please tell me whom you saw yesterday.
(b) 直接疑问句:Which room do you prefer ？
间接疑问句:He wanted to know which room I preferred.