4 sentences

1. 我给你计时。

   wǒ gěi nǐ jì​shí.

   I'll time you.

   Source: OpenSubtitles

2. 裁判正在为百米赛跑的运动员计时。

   cái​pàn zhèng​zài wèi bǎi mǐ sài​pǎo de yùn​dòng​yuán jì​shí.

   The referee is timing the 100-meter runners.

   Source: Dong Chinese Dictionary

3. 古代的人们通过观测漏壶中的水位来计时。

   gǔ​dài de rén​men tōng​guò guān​cè lòu hú zhōng de shuǐ​wèi lái jì​shí.

   Ancient people kept time by observing the water level in a clepsydra.

   Source: Dong Chinese Dictionary

4. 这家网吧是按小时计时的。

   zhè jiā wǎng​bā shì àn xiǎo​shí jì​shí de.

   This internet cafe charges by the hour.

   Source: Dong Chinese Dictionary