1.一般疑问句改成宾语从句时,先在从句前加上if/whether,然后把它变成陈述句序即可,当然也要注意时态的变化和some/any的变化.
如：Can you play football?
→ I don't know if/whether you can play football.
2.陈述句改成宾语从句时,先在从句前加上that（也可以不加）,照抄即可,当然也要注意时态的变化.
如：She is a student.
→ He said (that) she was a student.
3.特殊疑问句改成宾语从句时,疑问词不变依然放在从句句首,其后变成陈述句序,当然也要注意时态等变化.
如：How old is he?
→ I wanted to know how old he was.