He wants to know does he often singing He wants to know he o

两句都有语法问题.
第一句,在从句里,比如定语从句,表语从句和宾语从句等从句中要用正装语序,即陈述句语序,也就是主谓宾的排列.
而第二句,语序倒是用来正装语序,但是does singging 没有这么一说,而singing又是个动名词,不能做谓语,谓语要用动词或者相当于动词的词来充当.
所以,你要表示的正确的句子是 he wants to konw whether/if he often sings.
好了,我就不赘述了,我的回答只是希望给你个启示,