I could mount you could mount he could mount we could mount you could mount they could mount
V-ing form
I could be mounting you could be mounting he could be mounting we could be mounting you could be mounting they could be mounting
Perfect
I could have mounted you could have mounted he could have mounted we could have mounted you could have mounted they could have mounted
V-ing perfect
I could have been mounting you could have been mounting he could have been mounting we could have been mounting you could have been mounting they could have been mounting
Negation
Simple form
I could not mount you could not mount he could not mount we could not mount you could not mount they could not mount
V-ing form
I could not be mounting you could not be mounting he could not be mounting we could not be mounting you could not be mounting they could not be mounting
Perfect
I could not have mounted you could not have mounted he could not have mounted we could not have mounted you could not have mounted they could not have mounted
V-ing perfect
I could not have been mounting you could not have been mounting he could not have been mounting we could not have been mounting you could not have been mounting they could not have been mounting
Interrogative form
Simple form
could I mount? could you mount? could he mount? could we mount? could you mount? could they mount?
V-ing form
could I be mounting? could you be mounting? could he be mounting? could we be mounting? could you be mounting? could they be mounting?
Perfect
could I have mounted? could you have mounted? could he have mounted? could we have mounted? could you have mounted? could they have mounted?
V-ing perfect
could I have been mounting? could you have been mounting? could he have been mounting? could we have been mounting? could you have been mounting? could they have been mounting?
Interro-negative form
Simple form
could I not mount? could you not mount? could he not mount? could we not mount? could you not mount? could they not mount?
V-ing form
could I not be mounting? could you not be mounting? could he not be mounting? could we not be mounting? could you not be mounting? could they not be mounting?
Perfect
could I not have mounted? could you not have mounted? could he not have mounted? could we not have mounted? could you not have mounted? could they not have mounted?
V-ing perfect
could I not have been mounting? could you not have been mounting? could he not have been mounting? could we not have been mounting? could you not have been mounting? could they not have been mounting?