The clever boy made a hole in the wall(through which)he could see(what)was going on inside the hous

问题描述:

The clever boy made a hole in the wall(through which)he could see(what)was going on inside the hous
为什么不是用through that ,what,

wall 后是一个定语从句,而引导定语从句只能用介词+which,不能用that,
what不能引导定语从句he could see(what)was going on inside the house,应该是个定语从句吧,如果按你说What不能引导定语从句,那么后面就不能填What了,对不?后面what 从句是定语从句中的宾语从句.