ask后的宾语从句连词可以用很多哦·,要看具体意思
1) if和whether都可以
如：He asked if Mr.Gilbert 's operation had been successful .
他问吉尔伯特先生的手术中否成功.
He asked whether the man were a Chinese 他问那个男人是不是中国人
2）还有就是关系代词what,why,where,when,how,who等都可以.
如：He asked me what I did in my free time .
他问我业余时间做什么.
He asked me when he would see me again.
他问我什么时候他还能见到我.
3）that 也可以
如：He asked that he be given an opportunity to try .
他要求给他一个试试的机会.