1. Lunch is a big meal of the day
=> Lunch isn't a big meal of the day
=> Is lunch a big meal of the day ?
2. These workers want some iced water
=> These workers don't want some iced water
=> Do these workers want some iced water ?
3. My father is listening to the radio now
=> My father isn't listening to the radio now ?
=> Is your father listening to the radio now ?
4. Mary drinks some coffee for breakfast
=> Mary doesn't drink some coffee for breakfast
=> Does Mary drink some coffee for breakfast ?
5. Nam and Mai like ice cream
=> Nam and Mai don't like ice cream
=> Do Nam and Mai like ice cream ?