how come?

Idioms  

1. How is it that, as in How come you're not attending the conference? Sometimes how come follows a statement and asks the question “why” or “in what way,” as in You're not going? How come? The related phrase how so? functions the same way, as in You say she's changed her mind—how so? How come is short for how did it come about that and dates from the mid-1800s; how so, short for how is it so or how is it that, dates from about 1300.

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Example Sentences

“How come I’ve never seen you around before? Are you new here?”

From Literature

“How come Rhys wasn’t there? Thought for sure he’d be in the front row, cheering you on.”

From Literature

“Let me ask you something. How come all of Fernlight Forest is talking about a half-dead fox who showed up to Ragginold’s birthday looking for information about his long-gone mommy?”

From Literature

How come Duke keeps falling apart like that in huge contests?

From The Wall Street Journal

So if “we’re just going to say that historically it needs to look like it always looked, how come those features fall out?”

From Slate