wherefore
adv.& conj.为什么； 为此,因此
n.原因,理由
Wherefore did you go there?你为什么去那儿?
本句相当于Why did you go there?
He was angry,wherefore I was afraid to ask him.他发火了,所以我不敢去问他
本句相当于He was angry,so that I was afraid to ask him.
how
adv.怎样； 健康状况如何； 到何种地步； 以任何方式
n.方法； 方式
疑问词
（用于询问方式、方法）怎样,怎么,如何
You use how to ask about the way in which something happens or is done.
CONJ-SUBORD
连词
（用于某些形容词和动词后引出陈述或事实,常指记起之事或希望他人了解之事） You use how after certain adjectives and verbs to introduce a statement or fact,often something that you remember or expect other people to know about.
以上how所用情况均不能用why替代