English verb conjugation
MUST BACKGROUND

Regular verb: background - backgrounded - backgrounded

Affirmation

Simple form	V-ing form
I must background you must background she must background we must background you must background they must background	I must be backgrounding you must be backgrounding she must be backgrounding we must be backgrounding you must be backgrounding they must be backgrounding
Perfect	V-ing perfect
I must have backgrounded you must have backgrounded she must have backgrounded we must have backgrounded you must have backgrounded they must have backgrounded	I must have been backgrounding you must have been backgrounding she must have been backgrounding we must have been backgrounding you must have been backgrounding they must have been backgrounding

Negation

Simple form	V-ing form
I must not background you must not background she must not background we must not background you must not background they must not background	I must not be backgrounding you must not be backgrounding she must not be backgrounding we must not be backgrounding you must not be backgrounding they must not be backgrounding
Perfect	V-ing perfect
I must not have backgrounded you must not have backgrounded she must not have backgrounded we must not have backgrounded you must not have backgrounded they must not have backgrounded	I must not have been backgrounding you must not have been backgrounding she must not have been backgrounding we must not have been backgrounding you must not have been backgrounding they must not have been backgrounding

Interrogative form

Simple form	V-ing form
must I background? must you background? must she background? must we background? must you background? must they background?	must I be backgrounding? must you be backgrounding? must she be backgrounding? must we be backgrounding? must you be backgrounding? must they be backgrounding?
Perfect	V-ing perfect
must I have backgrounded? must you have backgrounded? must she have backgrounded? must we have backgrounded? must you have backgrounded? must they have backgrounded?	must I have been backgrounding? must you have been backgrounding? must she have been backgrounding? must we have been backgrounding? must you have been backgrounding? must they have been backgrounding?

Interro-negative form

Simple form	V-ing form
must I not background? must you not background? must she not background? must we not background? must you not background? must they not background?	must I not be backgrounding? must you not be backgrounding? must she not be backgrounding? must we not be backgrounding? must you not be backgrounding? must they not be backgrounding?
Perfect	V-ing perfect
must I not have backgrounded? must you not have backgrounded? must she not have backgrounded? must we not have backgrounded? must you not have backgrounded? must they not have backgrounded?	must I not have been backgrounding? must you not have been backgrounding? must she not have been backgrounding? must we not have been backgrounding? must you not have been backgrounding? must they not have been backgrounding?