Replace the infinites in brackets by the Present Indefinite, Present Continuous or Present Perfect Continuous.
1. Where are the pupils? - They (to plant) trees. They (to plant) them since the morning. They always (to plant) trees in October. They already (to plant) several hundred threes this year. 2. Ann (to have) her music lesson now. She (to have) her music lessons twice a week. I am going to take a walk. I (to do) all my home exercies already. I (to do) them for three hours. 4. Since when they (to build) this house? 5. At last I (to find) the book I need. I (to look for) it for a quarter of an hour. 6. Don't shout. Helen ( to read) an English book. She ( to work) at her English every day. She ( to learn) this language for three years. She ( to read) many English stories this year. 7. What you (to do) in the morning? 8. What you (to do) since the morning?

1. Where are the pupils? - They (are planting) trees. They (have been planting) them since the morning. They always (plant) trees in October. They have already (planted) several hundred threes this year. 2. Ann (is having) her music lesson now. She (has) her music lessons twice a week. I am going to take a walk. I (have  done) all my home exercies already. I (have been doing) them for three hours. 4. Since when have they (been building) this house? 5. At last I (have  found) the book I need. I (have been looking for) it for a quarter of an hour. 6. Don't shout. Helen (is reading) an English book. She (works) at her English every day. She (has been learning) this language for three years. She (has read) many English stories this year. 7. What are you ( doing) in the morning? 8. What have you (been doing) since the morning?