Work in pairs. Which of the sentences in Exercise 1a are true for you? Change the others so they're true.
Complete the sentences with was(n't) or were(n't).
1. I _ happy yesterday, but today I am.
2. We _ in Mexico for our holiday last summer, it was great.
3. _ you at home last night?
4. They _ at the office yesterday because they _ at a conference.
5. The teacher _ here yesterday because she _ on holiday.