Question

Use the past perfect continuous tense form of the verb in the following sentence:
We __________ to start up the computer for ten minutes before Tony remembered the password.

• A. were trying
• B. had been trying
• C. had tried
• D. tried

Answer 1

Answer: (B)

had been trying

Here, had been trying in Past Perfect Continuous Tense is correct because it is used to indicate an action in the past that began before a certain point in the past and continued up untill that time. Here, ten minutes in the sentence indicate an action in the past that began before a certain point in the past.
'Were trying' in past continuous is incorrect because it is used to indicate uncompleted action in the past (with or without time reference).
'Had tried' in past perfect is incorrect because it is used to indicate a completed action of the past that happened before another event took place.
'Tried' in past simple is incorrect because it indicates an action that has already been completed.