Present progressive form
am, is, are + present participle

• for actions in progress at the present time

• for future actions (with leave, go, come, move, etc.)

The students are taking an exam in Room 105.

I am leaving tomorrow morning.

Past progressive form
was, were + present participle

• for actions that were in progress at a specific past time

• for a continuing action that was interrupted by another action

The students were taking an exam in Room 105.

They were swimming when the storm struck.

Future progressive form
will + be + present participle

• for actions that will be in progress at a specific time in the future

The students will be taking an exam in Room 105 tomorrow morning.

Brad will be cooking when his parents arrive.

Present perfect progressive form
have, has + been + present participle

• for continuous actions that began in the past and continue to the present

My sister has been trying to get a job in Boston for five years.

Past perfect progressive form
had + been + present participle

• actions that began and continued in the past until some other past action

By the time I entered high school, I had been taking piano lessons for eight years.

Future perfect progressive form
will + be + present participle

• for actions that are or will be in progress before a specified time in the future

When Carol is eighty years old, she will have been living in Vermont for sixty-two years.