Here are the correct forms of the verbs for each sentence:

5. He (talk) **talked** to us for hours about all the interesting things he had.
6. She (stand) **was standing** looking at that picture for twenty minutes.
7. I (spend) **have spent** a lot of time travelling since I (get) **got** this new job.
8. When we were at school, we (study) **studied** Latin.
9. When I met him, he (work) **was working** as a waiter.