I could balance you could balance he could balance we could balance you could balance they could balance
V-ing form
I could be balancing you could be balancing he could be balancing we could be balancing you could be balancing they could be balancing
Perfect
I could have balanced you could have balanced he could have balanced we could have balanced you could have balanced they could have balanced
V-ing perfect
I could have been balancing you could have been balancing he could have been balancing we could have been balancing you could have been balancing they could have been balancing
Negation
Simple form
I could not balance you could not balance he could not balance we could not balance you could not balance they could not balance
V-ing form
I could not be balancing you could not be balancing he could not be balancing we could not be balancing you could not be balancing they could not be balancing
Perfect
I could not have balanced you could not have balanced he could not have balanced we could not have balanced you could not have balanced they could not have balanced
V-ing perfect
I could not have been balancing you could not have been balancing he could not have been balancing we could not have been balancing you could not have been balancing they could not have been balancing
Interrogative form
Simple form
could I balance? could you balance? could he balance? could we balance? could you balance? could they balance?
V-ing form
could I be balancing? could you be balancing? could he be balancing? could we be balancing? could you be balancing? could they be balancing?
Perfect
could I have balanced? could you have balanced? could he have balanced? could we have balanced? could you have balanced? could they have balanced?
V-ing perfect
could I have been balancing? could you have been balancing? could he have been balancing? could we have been balancing? could you have been balancing? could they have been balancing?
Interro-negative form
Simple form
could I not balance? could you not balance? could he not balance? could we not balance? could you not balance? could they not balance?
V-ing form
could I not be balancing? could you not be balancing? could he not be balancing? could we not be balancing? could you not be balancing? could they not be balancing?
Perfect
could I not have balanced? could you not have balanced? could he not have balanced? could we not have balanced? could you not have balanced? could they not have balanced?
V-ing perfect
could I not have been balancing? could you not have been balancing? could he not have been balancing? could we not have been balancing? could you not have been balancing? could they not have been balancing?