1.      1. I (live)           have lived                  here since 1989.

2.      2. They (work)         has worked                    for this factory for 20 years.

3.      3. He (read)              has read                this novel three times.

4.      4. Hoa and I (know)         has known                     each other since we were at the same class.

5.      5. I (not/see)      did not saw                    her since last month.

6.      6. I (not/work)     did not worked                       have not worked today.

7.      7. We (buy)       buys                     a new lamp.

8.      8. We (not/plan)      have not planed                     our holiday yet.

9.      9. Where (be/you)   are you                            ?

10.  10. He (write)          writes                     five letters.