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 must not regret you must not regret he must not regret we must not regret you must not regret they must not regret	I must not be regreting you must not be regreting he must not be regreting we must not be regreting you must not be regreting they must not be regreting
Perfect	V-ing perfect
I must not have regreted you must not have regreted he must not have regreted we must not have regreted you must not have regreted they must not have regreted	I must not have been regreting you must not have been regreting he must not have been regreting we must not have been regreting you must not have been regreting they must not 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
must I not regret? must you not regret? must he not regret? must we not regret? must you not regret? must they not regret?	must I not be regreting? must you not be regreting? must he not be regreting? must we not be regreting? must you not be regreting? must they not be regreting?
Perfect	V-ing perfect
must I not have regreted? must you not have regreted? must he not have regreted? must we not have regreted? must you not have regreted? must they not have regreted?	must I not have been regreting? must you not have been regreting? must he not have been regreting? must we not have been regreting? must you not have been regreting? must they not have been regreting?