(a) negative
1. Liz is not trying to fix her washing machine.
2. We were not having lunch when our uncle came.
3. She has not started her new job.
4. By the end of the year he had not learnt to speak French.
5. My secretary has not been typing the report for five hours.
(b) interrogative.
1. Is Liz trying to fix her washing machine?
2. Were we having lunch when our uncle came?
3. Has she started her new job?
4. Had helearnt to speak French by the end of the year?
5. Has my secretary been typing the report for five hours?