Lin Tao thought(that)the TV play was very boring.
David asked his mother if/ whether she liked the dinner last night.
3. 当宾语从句是由特殊疑问句变化而来时，原句中的疑问词充当连接代词(如who， whose， what， which)或连接副词(如when， where， why， how)，引导宾语从句。例如：
Do you know what we can do on the island?
I don’t know why Jane was late for school this morning.
When did he leave? I want to know. →I want to know when he left.
Does the shop close at six every day? Do you know? →Do you know if/ whether the shop closes at six every day?
I hear she is here today(she was here yesterday/ she will be here tomorrow.)
He said he was watching TV(he had swept the floor/ he would play football after school)。
Our teacher told us that light travels faster than sound.
当主句的谓语动词为think， believe， suppose等动词，且主语为第一人称时，从句的否定要转移到主句上。例如：
I don’t believe he is here on time， is he?
I don’t think Tom is the best student in his class， is he?