Come again can mean 'say it again'?

[Torsten]

Hi,

It just occurred to me that 'come again?' can mean 'could you repeat that, please'? It wasn't until I read this paragraph in "The Abduction" by James Grippando:

"And," said Harley, "there's something else you should know. Your father called earlier this morning. He's agreed to pay a ransom."
Tanya paused, seeming to catch her breath. "Don't deliver it."
"Come again?" said Allison.
"You're being set up."
"Set up?" asked Harley. "How?"

How often do you say "come again?" when you want somebody to repeat something they've just said?

TOEIC listening, talks: Weather forecast on radio

[Prezbucky]

I rarely use "come again?", but I have used it and know what it means. Probably most Americans know what it means.

It is informal and, as such, used among friends/family or (at least) those with whom one is familiar.

If I were to ask my boss to repeat himself, I'd say "Pardon me?" or "Could you repeat that, please?".
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