（Ｘ）How much is his income?
（Ｏ）What is his income?
（Ｏ）What does he earn?
（Ｏ）How much does he earn?
Income是一筆錢，用what問。但How much does he earn? 文法上是可以的。這裡省略掉money，原來是How much (money) does he earn?
（Ｘ）How much is your budget?
（O）What is your budget?
其實不只是錢，只要任何含有數字概念的名詞，像temperature是溫度、population是人口數目，這類東西問多少的時候，都用what 而不是how much。
（Ｘ）How much is the temperature outside?
（Ｏ）What is the temperature outside?
（Ｘ）How much is the population of Tokyo?
（Ｏ）What is the population of Tokyo?
本文經授權轉載自世界公民文化中心。（原標題：面試中問薪水＂How much is the salary?”哪裡不對了 ）