1. What are you | I (to do) here? 2. Who has (to write) this article? 3. What language are you (to study)? 4. We have already (to learn) a lot of English words. 5. What is she (to teach) them? 6. Who has (to teach) you to do it? 7. He has just (to do) something for us. 8. Have you (to find) the book? 9. We have just (to talk) about it. 10. He has just (to say) something about it.
1. doing
2. Written
3. Studying
4. Learnt
5. Teaching
6. Tough
7. Done
8. Found
9. Talked
10. Said