English verb conjugation
MUST EXCUSE

Regular verb: excuse - excused - excused

Affirmation

Simple form	V-ing form
I must excuse you must excuse she must excuse we must excuse you must excuse they must excuse	I must be excusing you must be excusing she must be excusing we must be excusing you must be excusing they must be excusing
Perfect	V-ing perfect
I must have excused you must have excused she must have excused we must have excused you must have excused they must have excused	I must have been excusing you must have been excusing she must have been excusing we must have been excusing you must have been excusing they must have been excusing

Negation

Simple form	V-ing form
I must not excuse you must not excuse she must not excuse we must not excuse you must not excuse they must not excuse	I must not be excusing you must not be excusing she must not be excusing we must not be excusing you must not be excusing they must not be excusing
Perfect	V-ing perfect
I must not have excused you must not have excused she must not have excused we must not have excused you must not have excused they must not have excused	I must not have been excusing you must not have been excusing she must not have been excusing we must not have been excusing you must not have been excusing they must not have been excusing

Interrogative form

Simple form	V-ing form
must I excuse? must you excuse? must she excuse? must we excuse? must you excuse? must they excuse?	must I be excusing? must you be excusing? must she be excusing? must we be excusing? must you be excusing? must they be excusing?
Perfect	V-ing perfect
must I have excused? must you have excused? must she have excused? must we have excused? must you have excused? must they have excused?	must I have been excusing? must you have been excusing? must she have been excusing? must we have been excusing? must you have been excusing? must they have been excusing?

Interro-negative form

Simple form	V-ing form
must I not excuse? must you not excuse? must she not excuse? must we not excuse? must you not excuse? must they not excuse?	must I not be excusing? must you not be excusing? must she not be excusing? must we not be excusing? must you not be excusing? must they not be excusing?
Perfect	V-ing perfect
must I not have excused? must you not have excused? must she not have excused? must we not have excused? must you not have excused? must they not have excused?	must I not have been excusing? must you not have been excusing? must she not have been excusing? must we not have been excusing? must you not have been excusing? must they not have been excusing?