I could wolf you could wolf he could wolf we could wolf you could wolf they could wolf
V-ing form
I could be wolfing you could be wolfing he could be wolfing we could be wolfing you could be wolfing they could be wolfing
Perfect
I could have wolfed you could have wolfed he could have wolfed we could have wolfed you could have wolfed they could have wolfed
V-ing perfect
I could have been wolfing you could have been wolfing he could have been wolfing we could have been wolfing you could have been wolfing they could have been wolfing
Negation
Simple form
I could not wolf you could not wolf he could not wolf we could not wolf you could not wolf they could not wolf
V-ing form
I could not be wolfing you could not be wolfing he could not be wolfing we could not be wolfing you could not be wolfing they could not be wolfing
Perfect
I could not have wolfed you could not have wolfed he could not have wolfed we could not have wolfed you could not have wolfed they could not have wolfed
V-ing perfect
I could not have been wolfing you could not have been wolfing he could not have been wolfing we could not have been wolfing you could not have been wolfing they could not have been wolfing
Interrogative form
Simple form
could I wolf? could you wolf? could he wolf? could we wolf? could you wolf? could they wolf?
V-ing form
could I be wolfing? could you be wolfing? could he be wolfing? could we be wolfing? could you be wolfing? could they be wolfing?
Perfect
could I have wolfed? could you have wolfed? could he have wolfed? could we have wolfed? could you have wolfed? could they have wolfed?
V-ing perfect
could I have been wolfing? could you have been wolfing? could he have been wolfing? could we have been wolfing? could you have been wolfing? could they have been wolfing?
Interro-negative form
Simple form
could I not wolf? could you not wolf? could he not wolf? could we not wolf? could you not wolf? could they not wolf?
V-ing form
could I not be wolfing? could you not be wolfing? could he not be wolfing? could we not be wolfing? could you not be wolfing? could they not be wolfing?
Perfect
could I not have wolfed? could you not have wolfed? could he not have wolfed? could we not have wolfed? could you not have wolfed? could they not have wolfed?
V-ing perfect
could I not have been wolfing? could you not have been wolfing? could he not have been wolfing? could we not have been wolfing? could you not have been wolfing? could they not have been wolfing?