3. (+) My father keeps the greenhouse warm at night.
(?) Does your father keep the greenhouse warm at night?
4. (+) Danny remembers to phone his father on Sundays.
(-) Danny doesn't remember to phone his farther on Sundays.
5. (+) They do their homework after school.
(?) Do they do their homework after school?
__
(+) S + Vs/es + O
(-) S + don't/doesn't + V-inf + O
(?) Do/does + S + V-inf +O?