核心问题
张道真教授编著的《英语语法大全》(外研社,1998,p.367)在 §591 中将 how 看作是关系副词,并作了如下阐述:
“how 是表示方式的副词, 必须放在表示方式的名词后面, 总是用在限制性关系从句中, 而且通常都省略:
This is the manner (how) (= in which) you treat me. Can you tell me the way (how) he did it? This is the way (how) it was and will always be. That (or This) is how (= the way how) he got rich. (这里先行词未出现)”
词典解答
《英语语法大全》关于 how 用作关系副词的论述是不符合英语实际的，见 how 。附带提出，That is how he got rich. 的说法是正确的，而 That is the way how he got rich. 的说法却是错误的。