灰

In a sentence

• 我打扫房间时发现了很多灰。

  I found a lot of dust when cleaning the room.

  Here, '灰' refers to 'dust', indicating particulate matter often accumulated in uncleaned spaces.

• 她穿着一件灰色的大衣，看起来很优雅。

  She is wearing a gray coat, looking very elegant.

  In this sentence, '灰' is used as '灰色' (gray), denoting a color.

• 经历了失败，他的心情变得很灰暗。

  After experiencing failure, his mood became very gloomy.

  Here, '灰' forms '灰暗' (gloomy), symbolizing a pessimistic or depressed mental state.