3 sentences

1. 如果他没空，我代他去开会。

   rú​guǒ tā méi​kòng, wǒ dài tā qù kāi​huì.

   If he's not available, I'll go to the meeting in his place.

   Source: Dong Chinese Dictionary

2. 我今朝没空。

   wǒ jīn​zhāo méi​kòng.

   I don't have time today.

   Source: Dong Chinese Dictionary

3. 我今天下午要加班，所以没空陪你去逛街。

   wǒ jīn​tiān xià​wǔ yào jiā​bān, suǒ​yǐ méi​kòng péi nǐ qù guàng​jiē.

   I have to work overtime this afternoon, so I don't have time to go shopping with you.

   Source: Dong Chinese Dictionary