I could institute you could institute he could institute we could institute you could institute they could institute
V-ing form
I could be instituting you could be instituting he could be instituting we could be instituting you could be instituting they could be instituting
Perfect
I could have instituted you could have instituted he could have instituted we could have instituted you could have instituted they could have instituted
V-ing perfect
I could have been instituting you could have been instituting he could have been instituting we could have been instituting you could have been instituting they could have been instituting
Negation
Simple form
I couldn't institute you couldn't institute he couldn't institute we couldn't institute you couldn't institute they couldn't institute
V-ing form
I couldn't be instituting you couldn't be instituting he couldn't be instituting we couldn't be instituting you couldn't be instituting they couldn't be instituting
Perfect
I couldn't have instituted you couldn't have instituted he couldn't have instituted we couldn't have instituted you couldn't have instituted they couldn't have instituted
V-ing perfect
I couldn't have been instituting you couldn't have been instituting he couldn't have been instituting we couldn't have been instituting you couldn't have been instituting they couldn't have been instituting
Interrogative form
Simple form
could I institute? could you institute? could he institute? could we institute? could you institute? could they institute?
V-ing form
could I be instituting? could you be instituting? could he be instituting? could we be instituting? could you be instituting? could they be instituting?
Perfect
could I have instituted? could you have instituted? could he have instituted? could we have instituted? could you have instituted? could they have instituted?
V-ing perfect
could I have been instituting? could you have been instituting? could he have been instituting? could we have been instituting? could you have been instituting? could they have been instituting?
Interro-negative form
Simple form
couldn't I institute? couldn't you institute? couldn't he institute? couldn't we institute? couldn't you institute? couldn't they institute?
V-ing form
couldn't I be instituting? couldn't you be instituting? couldn't he be instituting? couldn't we be instituting? couldn't you be instituting? couldn't they be instituting?
Perfect
couldn't I have instituted? couldn't you have instituted? couldn't he have instituted? couldn't we have instituted? couldn't you have instituted? couldn't they have instituted?
V-ing perfect
couldn't I have been instituting? couldn't you have been instituting? couldn't he have been instituting? couldn't we have been instituting? couldn't you have been instituting? couldn't they have been instituting?