English verb conjugation
MUST MUFF

Regular verb: muff - muffed - muffed

Affirmation

Simple form	V-ing form
I must muff you must muff she must muff we must muff you must muff they must muff	I must be muffing you must be muffing she must be muffing we must be muffing you must be muffing they must be muffing
Perfect	V-ing perfect
I must have muffed you must have muffed she must have muffed we must have muffed you must have muffed they must have muffed	I must have been muffing you must have been muffing she must have been muffing we must have been muffing you must have been muffing they must have been muffing

Negation

Simple form	V-ing form
I must not muff you must not muff she must not muff we must not muff you must not muff they must not muff	I must not be muffing you must not be muffing she must not be muffing we must not be muffing you must not be muffing they must not be muffing
Perfect	V-ing perfect
I must not have muffed you must not have muffed she must not have muffed we must not have muffed you must not have muffed they must not have muffed	I must not have been muffing you must not have been muffing she must not have been muffing we must not have been muffing you must not have been muffing they must not have been muffing

Interrogative form

Simple form	V-ing form
must I muff? must you muff? must she muff? must we muff? must you muff? must they muff?	must I be muffing? must you be muffing? must she be muffing? must we be muffing? must you be muffing? must they be muffing?
Perfect	V-ing perfect
must I have muffed? must you have muffed? must she have muffed? must we have muffed? must you have muffed? must they have muffed?	must I have been muffing? must you have been muffing? must she have been muffing? must we have been muffing? must you have been muffing? must they have been muffing?

Interro-negative form

Simple form	V-ing form
must I not muff? must you not muff? must she not muff? must we not muff? must you not muff? must they not muff?	must I not be muffing? must you not be muffing? must she not be muffing? must we not be muffing? must you not be muffing? must they not be muffing?
Perfect	V-ing perfect
must I not have muffed? must you not have muffed? must she not have muffed? must we not have muffed? must you not have muffed? must they not have muffed?	must I not have been muffing? must you not have been muffing? must she not have been muffing? must we not have been muffing? must you not have been muffing? must they not have been muffing?