I could pet you could pet he could pet we could pet you could pet they could pet
V-ing form
I could be petting you could be petting he could be petting we could be petting you could be petting they could be petting
Perfect
I could have petted you could have petted he could have petted we could have petted you could have petted they could have petted
V-ing perfect
I could have been petting you could have been petting he could have been petting we could have been petting you could have been petting they could have been petting
Negation
Simple form
I could not pet you could not pet he could not pet we could not pet you could not pet they could not pet
V-ing form
I could not be petting you could not be petting he could not be petting we could not be petting you could not be petting they could not be petting
Perfect
I could not have petted you could not have petted he could not have petted we could not have petted you could not have petted they could not have petted
V-ing perfect
I could not have been petting you could not have been petting he could not have been petting we could not have been petting you could not have been petting they could not have been petting
Interrogative form
Simple form
could I pet? could you pet? could he pet? could we pet? could you pet? could they pet?
V-ing form
could I be petting? could you be petting? could he be petting? could we be petting? could you be petting? could they be petting?
Perfect
could I have petted? could you have petted? could he have petted? could we have petted? could you have petted? could they have petted?
V-ing perfect
could I have been petting? could you have been petting? could he have been petting? could we have been petting? could you have been petting? could they have been petting?
Interro-negative form
Simple form
could I not pet? could you not pet? could he not pet? could we not pet? could you not pet? could they not pet?
V-ing form
could I not be petting? could you not be petting? could he not be petting? could we not be petting? could you not be petting? could they not be petting?
Perfect
could I not have petted? could you not have petted? could he not have petted? could we not have petted? could you not have petted? could they not have petted?
V-ing perfect
could I not have been petting? could you not have been petting? could he not have been petting? could we not have been petting? could you not have been petting? could they not have been petting?