4 sentences for 係 (hai)

1. 你系唔系唔中意我咩？

   nǐ hai wú hai wú zhòng​yì wǒ miē?

   Is it that you don't like me?

   Source: Dong Chinese Dictionary

2. 我唔知佢系边个。

   wǒ wú zhī qú hai bīn​gǒ.

   I don't know who he is.

   Source: Dong Chinese Dictionary

3. 呢本书系我嘅。

   ne běn shū hai wǒ gě.

   This book is mine.

   Source: Dong Chinese Dictionary

4. 我系学生。

   wǒ hai xué​sheng.

   I am a student.

   Source: Dong Chinese Dictionary