must background
Verbe régulier : background - backgrounded- backgrounded

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
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	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	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
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	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	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
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? 	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? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
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? 	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?