What it means

Please say that again. 再 is "again," 一遍 is "one time through."

When to use it

Perfectly polite. Add 慢一点 for "say it again, slower" — the combination covers most listening emergencies.

bù不hǎo好yì意sī思，qǐng请zài再shuō说yī一biàn遍。

Sorry, please say that again.

qǐng请zài再shuō说yī一biàn遍，wǒ我méi没tīng听qīng清。

Please say it again, I didn't catch it.

néng能bù不néng能qǐng请zài再shuō说yī一biàn遍？

Could you please say that again?

The full set of survival phrases for greetings, dining, shopping, and getting around, each with audio.