1. When the manager arrived he noticed/was noticing that the secretary had left.
2. I was trying/tried to get in touch with your secretary all day yesterday but I couldn’t.
3. He typed/was typing the contract when his boss came/was coming in.
4. What did you do/were you doing yesterday as I tried/was trying to get through to you?
5. At that time he worked/was working in a pharmaceutical company.
6. I realised/was realising that somebody was ringing me up/rang me up as I was
going/went into the conference room.
7. My secretary did not understand/was not understanding how the new computer
programme was working/worked.
8. It was only later that I found out/was finding out there was somebody who knew/was
knowing that she spent/was spending time in prison at the time for tax evasion.
9. As nobody watched/was watching, it was easy for me to conduct the transaction my way.
10. He was going/went on his business trip to France when her plane crashed/was crashing.