Exercise on Past Perfect Progressive

Put the verbs into the correct form (past perfect progressive).

1. We (sleep) for 12 hours when he woke us up.
2. They (wait) at the station for 90 minutes when the train finally arrived.
3. We (look for) her ring for two hours and then we found it in the bathroom.
4. I (not / walk) for a long time, when it suddenly began to rain.
5. How long (learn / she) English before she went to London?
6. Frank Sinatra caught the flu because he (sing) in the rain too long.
7. He (drive) less than an hour when he ran out of petrol.
8. They were very tired in the evening because they (help) on the farm all day.
9. I (not / work) all day; so I wasn't tired and went to the disco at night.
10. They (cycle) all day so their legs were sore in the evening.