4 sentences for 知 (zhī — perceive)

1. 你知不知道这里是医院啊？

   nǐ zhī bù zhī​dào zhè​lǐ shì yī​yuàn a?

   Don't you know this is a hospital?

   Source: OpenSubtitles

2. 这是一个不为人知的秘密。

   zhè shì yī gè bù wéi rén zhī de mì​mì.

   This is a little-known secret.

   Source: Dong Chinese Dictionary

3. 他平时对家人非常体贴，是一个知冷知热的好丈夫。

   tā píng​shí duì jiā​rén fēi​cháng tǐ​tiē, shì yī gè zhī lěng zhī rè de hǎo zhàng​fu.

   He is usually very considerate of his family and is a caring husband who is attentive to his wife's every need.

   Source: Dong Chinese Dictionary

4. 他的旧衣服上不知在什么时候磨出了好几个大窟窿。

   tā de jiù yī​fu shàng bù zhī zài shén​me shí​hou mó chū le hǎo​jǐ gè dà kū​long.

   At some point, several large holes had been worn into his old clothes.

   Source: Dong Chinese Dictionary