This is good specifically for the present perfect in the passive or active. You may need to pre-teach some vocabulary depending on the learners.
- Divide the class into two groups.
- One group will leave the room for a few minutes while the other group changes a few things in the classroom (you might give an exact number, say 8).
- When the group outside returns to the room, they need to identify the things that are different using target language such as: The picture has been hung upside down./The dictionary has been moved. (active voice: You have hung… /Someone has moved…)
- Award points for the correct answers/grammar.
For 1-1: Play as described above.