could concuss
Regular verb: concuss - concussed- concussed

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

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't concuss
you couldn't concuss
she couldn't concuss
we couldn't concuss
you couldn't concuss
they couldn't concuss 	I couldn't be concussing
you couldn't be concussing
she couldn't be concussing
we couldn't be concussing
you couldn't be concussing
they couldn't be concussing	I couldn't have concussed
you couldn't have concussed
she couldn't have concussed
we couldn't have concussed
you couldn't have concussed
they couldn't have concussed	I couldn't have been concussing
you couldn't have been concussing
she couldn't have been concussing
we couldn't have been concussing
you couldn't have been concussing
they couldn't have been concussing	

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

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