English verb conjugation
MUST REGRET

Regular verb: regret - regreted - regreted

Affirmation

Simple form	V-ing form
I must regret you must regret he must regret we must regret you must regret they must regret	I must be regreting you must be regreting he must be regreting we must be regreting you must be regreting they must be regreting
Perfect	V-ing perfect
I must have regreted you must have regreted he must have regreted we must have regreted you must have regreted they must have regreted	I must have been regreting you must have been regreting he must have been regreting we must have been regreting you must have been regreting they must have been regreting

Negation

Simple form	V-ing form
I mustn't regret you mustn't regret he mustn't regret we mustn't regret you mustn't regret they mustn't regret	I mustn't be regreting you mustn't be regreting he mustn't be regreting we mustn't be regreting you mustn't be regreting they mustn't be regreting
Perfect	V-ing perfect
I mustn't have regreted you mustn't have regreted he mustn't have regreted we mustn't have regreted you mustn't have regreted they mustn't have regreted	I mustn't have been regreting you mustn't have been regreting he mustn't have been regreting we mustn't have been regreting you mustn't have been regreting they mustn't have been regreting

Interrogative form

Simple form	V-ing form
must I regret? must you regret? must he regret? must we regret? must you regret? must they regret?	must I be regreting? must you be regreting? must he be regreting? must we be regreting? must you be regreting? must they be regreting?
Perfect	V-ing perfect
must I have regreted? must you have regreted? must he have regreted? must we have regreted? must you have regreted? must they have regreted?	must I have been regreting? must you have been regreting? must he have been regreting? must we have been regreting? must you have been regreting? must they have been regreting?

Interro-negative form

Simple form	V-ing form
mustn't I regret? mustn't you regret? mustn't he regret? mustn't we regret? mustn't you regret? mustn't they regret?	mustn't I be regreting? mustn't you be regreting? mustn't he be regreting? mustn't we be regreting? mustn't you be regreting? mustn't they be regreting?
Perfect	V-ing perfect
mustn't I have regreted? mustn't you have regreted? mustn't he have regreted? mustn't we have regreted? mustn't you have regreted? mustn't they have regreted?	mustn't I have been regreting? mustn't you have been regreting? mustn't he have been regreting? mustn't we have been regreting? mustn't you have been regreting? mustn't they have been regreting?