Change this passive sentence into active voice: Her lessons have been learned by her.

Which helping verb accompanies a future perfect tense verb?

John _________________ to travel to California next month, but he now can’t afford a plane ticket. (a. have planned b. had planned c. will have planned)

They will have finished working.

Which helping verb accompanies a past perfect tense verb?

Change this passive sentence into active voice: The thief has been caught by the police.

Change this passive sentence into active voice: A novel has been written by her.

She _________ the meal for one hour. (a. had been cooking b.has been cooking)

Change this active sentence into passive voice: Did she do her duty?

The mother took the child to the doctor.

Which perfect verb tense describes actions that have continued up to the present time, though there is uncertainty as to whether the actions will continue?

She has agreed to come.