Use the Present Perfect, the Present Perfect Continuous or the Present Continuous.
1. I (wait) for the prices of the houses to come down before buying a house, but I think I (wait) too long and the prices are beginning to go up again.
2. Call the children in! They (play) outside since early morning and (not to do) their homework yet.
3. I'm afraid she (not to finish) typing those letters yet. She (deal) with customers all morning.
4. You (fix) this shelf for an hour. Let's ask Father to help you.
5. The students (translate) the article for 20 minutes but they (not to finish) it yet.
Answers & Comments
2. Call the children in! They have been playing outside since early morning and have not done their homework yet.
3. I'm afraid she has not finished typing those letters yet. She has been dealing with customers all morning.
4. You have been fixing this shelf for an hour. Let's ask Father to help you.
5. The students have been translating the article for 20 minutes but they have not finished it yet.