1. Бие даалтын гэрийн даалгавар
4a. Study the present perfect continuous
sentences in activity 3c.Then choose a or b in
the explanations below.
1.We use present prefect continuous for
activities that
a. started in the past and were completed.
b. started in the past and haven’t been
completed.
2. We use since before
a. an exact point in time.
b. a period of time
3. We use for before
a. an exact point in time.
b. a period of time
4.To from the present prefect continuous we
use
a. have/has + verb –ing
b. have/has been+ verb –ing