3 sentences for 快 (kuài — sharp)

1. 这把刀一点也不快。

   zhè bǎ dāo yī​diǎn yě bù kuài.

   This knife is not at all sharp.

   Source: Tatoeba

2. 请把这把斧头的刃磨快。

   qǐng bǎ zhè bǎ fǔ​tou de rèn mó kuài.

   Please sharpen the edge of this axe.

   Source: AI Challenger 2017

3. 他在磨石上磨快了他的刀刃。

   tā zài mó​shí shang mó kuài le tā de dāo​rèn.

   He sharpened the edge of his knife on a grindstone.

   Source: UM-Corpus: Spoken