posted by rfvv .
1. He went to the teachers' room. There were many teachers, and he was able to see some students scolded by a teacher.
2. The native speaker has his office. In the teacher's office, we talked with the foreign speaker.
3. The teacher's room is a little small, so only 15 students can sit on their chairs.
4. The head teacher has his room. In the teacher's office, students learn Chinese characters.
(What expressions do we have to use? Teachers' room, teacher's room. teacher's office, teachers' office.)