what did he tell his wife that he wished to do?A.
问题描述：
what did he tell his wife that he wished to do?A.
此句中,that作何解释?
答
把这句话变成陈述句形式 he told his wife what that he wished to do.
这样很明了了吧,
what 是先行词.
that 引导的是一个定语从句