how come... In what way....

u use "how come" when u are wondering and clueless....it is a substitute for "why". this is an informal "why". I suggest that it will be more polite to use "why" unless u r communicating with someone u really know well.

例句： How come David is home? Isn't he feeling well? (戴维怎么会在家呢？他感觉不舒服吗？)

释义：用于你想知道为何某事或某种现象会发生或存在。（怎么会？为什么？） 例句： How come you're not at work today? 你今天怎么没上班呢？