Now Charlie is at work.
At midnight last night he wasn't at work.
He was in bed. He was asleep.
am /is (present) –> was (past):
- I am tired (now). I was tired last night.
- Is she at home (now)? Was she at home yesterday morning?
- The weather is nice today. The weather was nice yesterday.
are (present) –> were (past):
- You are late (now). You were late yesterday.
- They aren't here (now). They weren't here last Sunday.
- Last year she was 22, so she is 23 now.
- When I was a child, I was afraid of dogs.
- We were tired after the journey but we weren't hungry.
- The hotel was very comfortable and it wasn't expensive.
- Where were you at 3 o'clock yesterday afternoon?
- Was the weather good when you were on holiday?
- Those shoes are nice. Were they expensive?
- Why was he angry yesterday?
- 'Were you late? ' 'No, I wasn't.'
- 'Was Ted at work yesterday?' 'Yes, he was.'
- 'Were they at the party?' 'No, they weren't.'