上課時不能閒聊。

You can't chatter during class.

Source: Tatoeba

Sentence Composition

1 上課 shàngkè
  1. to go to class
  2. to attend class
  3. to go to teach a class
=2 時 Shí surname Shi
=2 時 shí
  1. o'clock
  2. time
  3. when
  4. hour
  5. season
  6. period
3 不能 bùnéng
  1. cannot
  2. must not
  3. should not
4 閒聊 xiánliáo
  1. to chat
  2. casual conversation