English verb conjugation
COULD CONCUSS

Regular verb: concuss - concussed - concussed

Affirmation

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