2 sentences

1. 你一定是听错了。

   nǐ yī​dìng shì tīng​cuò le.

   You must've misheard.

   Source: OpenSubtitles

2. 我是不是听错了？

   wǒ shì bù shì tīng​cuò le?

   Did I hear it wrong?

   Source: OpenSubtitles