1. They never come in time или they don't always come in time
Do they always come on time?
Do they always or seldom come on time?
They always come on time, don't they?
What do they do on time?
Who always comes on time?
2. Bill doesn't see his friends on Saturdays
Does Bill see his friends on Saturdays?
Does Bill see his friends on Saturdays or Fridays?
Bill sees his friends on Saturdays, doesn't he?
Who does Bill see on Saturdays?
Who sees the friends on Saturdays?