1. They used to play tennis twice a week.
`=>`
(-) They did not use to play tennis twice a week.
(?) Did they use to play tennis twice a week?
2. I used to go to the gym three times a week.
`=>`
(-) I did not use to go to the gym three times a week.
(?) Did you use to go to the gym three times a week ?
3. Tennis used to be a sport for rich people only.
`=>`
(-) Tennis did not use to be a sport for rich people only
(?) Did tennis use to be a sport for rich people only ?
4. My father used to take me to see soccer games on Saturday.
`=>`
(-) My father did not use to take me to see soccer games on Saturday.
(?) Did your father use to take you to see soccer games on Saturday ?
5. He used to buy a new tennis racket.
`=>`
(-) He did not use to buy a new tennis racket.
(?) Did he use to buy a new tennis racket ?