Past Simple or Past Perfect
1. We (have) a good rest when our guests all (leave).
2. When he (ring) the office this morning, Ann (alreade, leave).
3. We had to wait two hours at the airport because the bad weather (delay) all the flights.
4. They missed their train, so by the time they reached the theatre, the play (end) and the audience (leave) the theatre.

1. We had a good rest when our guests all had left.

2. When he rang the office this morning, Ann had already left.

3. We had to wait two hours at the airport because the bad weather had delayed all the flights.

4. They missed their train, so by the time they reached the theatre, the play ended and the audience left the theatre.