Replace the infinitive in brackets by the correct form of the verb.
1. We (to go) to school now. 2. The teacher (to explain) a grammar rule to the pupils now. 3. They (to read) an English text now. 4. Kate(to speak) English to her teacher at the lesson. 5. David (to describe) a picture now. 6. The students (to ask) questions to their teacher now. 7. Nick (to work) in his room now. 8. The teacher (to give) marks to the pupils now. 9. They (to play) in the yard now. 10. Henry (to write) a letter to his friend. 11. They (to write) a dictation now. 12. He (to write) an exercise on the blackboard now. 13. He is still (to write) his essay. 14. The pupils (to wait) for their teacher. 15. Mother (to watch) TV now