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

“We’re filing returns and people are saying how come my Social Security payments are getting taxed?”

From Barron's • Apr. 25, 2026

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 • Mar. 23, 2026

Filmmakers seem to take a special pleasure in depicting an apocalyptic future for Los Angeles — how come?

From Los Angeles Times • Aug. 10, 2025

“I’d be willing to have this arm cut off if I could understand how come the quantum? If I could understand how existence comes about,” Wheeler once said in a past interview.

From Salon • Jan. 17, 2025

“If you’re such a brainiac, how come you never skipped grades?”

From "Made You Up" by Francesca Zappia