Three Victorian ghosts are arguing about proper haunting etiquette.
Select ALL the sentences where their use of the marginal modal "ought" is grammatically correct.
The correct answers are Ought we to rattle the chains before or after midnight? and You ought not to wail so loudly when the master is sleeping.
Ought is unique because it acts like a modal auxiliary (it inverts for questions and takes "not" directly for negations) but it almost always requires a to-infinitive*.
Question form: Ought + subject + to + verb (Ought we to rattle...?)
Negative form: Ought + not + to + verb (You ought not to wail...)
"Didn't ought" and "Do we ought" are incorrect because "ought" does not take do-support in standard English. "We ought rattle" is incorrect because it is missing the mandatory "to".