1. John (has written) his name.
2. I (have drawn) a picture.
3. Tom (has switched on) the light.
4. The cat (has drunk) its milk.
5. John (has given) his bicycle to his brother.
6. You (have made) a mistake.
7. We (have eaten) our dinner.
8. The train has just (gone).
9. I have just (told) the answer.
10. George has never (been) in Australia.