1. Who was riding a bicycle yesterday?
   When was my father riding a bicycle?
   What was my father riding yesterday?
   What was my father doing yesterday?
   Was my father riding a bicycle yesterday?

2. Who will arrive tomorrow?
    When will my sister arrive?
    What will my sister do tomorrow?
    Will my sister arrive tomorrow?
    Will my sister arrive today or tomorrow?

3. Who plays tennis very well?
    What does Den do very well?
    Does Den play tennis well?
    What does Den play?
    Does Den play soccer or tennis very well?

4. What does Nick study?
    Who studies English at the courses on Mondays?
    When does Nick study English?
    Does Nick study English?
    Does Nick study English at the courses on Mondays or on Thursdays?