must concuss
Regular verb: concuss - concussed- concussed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must concuss
you must concuss
she must concuss
we must concuss
you must concuss
they must concuss 	I must be concussing
you must be concussing
she must be concussing
we must be concussing
you must be concussing
they must be concussing	I must have concussed
you must have concussed
she must have concussed
we must have concussed
you must have concussed
they must have concussed	I must have been concussing
you must have been concussing
she must have been concussing
we must have been concussing
you must have been concussing
they must have been concussing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not concuss
you must not concuss
she must not concuss
we must not concuss
you must not concuss
they must not concuss 	I must not be concussing
you must not be concussing
she must not be concussing
we must not be concussing
you must not be concussing
they must not be concussing	I must not have concussed
you must not have concussed
she must not have concussed
we must not have concussed
you must not have concussed
they must not have concussed	I must not have been concussing
you must not have been concussing
she must not have been concussing
we must not have been concussing
you must not have been concussing
they must not have been concussing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I concuss?
must you concuss?
must she concuss?
must we concuss?
must you concuss?
must they concuss? 	must I be concussing?
must you be concussing?
must she be concussing?
must we be concussing?
must you be concussing?
must they be concussing? 	must I have concussed?
must you have concussed?
must she have concussed?
must we have concussed?
must you have concussed?
must they have concussed? 	must I have been concussing?
must you have been concussing?
must she have been concussing?
must we have been concussing?
must you have been concussing?
must they have been concussing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not concuss?
must you not concuss?
must she not concuss?
must we not concuss?
must you not concuss?
must they not concuss? 	must I not be concussing?
must you not be concussing?
must she not be concussing?
must we not be concussing?
must you not be concussing?
must they not be concussing? 	must I not have concussed?
must you not have concussed?
must she not have concussed?
must we not have concussed?
must you not have concussed?
must they not have concussed? 	must I not have been concussing?
must you not have been concussing?
must she not have been concussing?
must we not have been concussing?
must you not have been concussing?
must they not have been concussing?