I could ta you could ta she could ta we could ta you could ta they could ta
V-ing form
I could be taing you could be taing she could be taing we could be taing you could be taing they could be taing
Perfect
I could have taed you could have taed she could have taed we could have taed you could have taed they could have taed
V-ing perfect
I could have been taing you could have been taing she could have been taing we could have been taing you could have been taing they could have been taing
Negation
Simple form
I could not ta you could not ta she could not ta we could not ta you could not ta they could not ta
V-ing form
I could not be taing you could not be taing she could not be taing we could not be taing you could not be taing they could not be taing
Perfect
I could not have taed you could not have taed she could not have taed we could not have taed you could not have taed they could not have taed
V-ing perfect
I could not have been taing you could not have been taing she could not have been taing we could not have been taing you could not have been taing they could not have been taing
Interrogative form
Simple form
could I ta? could you ta? could she ta? could we ta? could you ta? could they ta?
V-ing form
could I be taing? could you be taing? could she be taing? could we be taing? could you be taing? could they be taing?
Perfect
could I have taed? could you have taed? could she have taed? could we have taed? could you have taed? could they have taed?
V-ing perfect
could I have been taing? could you have been taing? could she have been taing? could we have been taing? could you have been taing? could they have been taing?
Interro-negative form
Simple form
could I not ta? could you not ta? could she not ta? could we not ta? could you not ta? could they not ta?
V-ing form
could I not be taing? could you not be taing? could she not be taing? could we not be taing? could you not be taing? could they not be taing?
Perfect
could I not have taed? could you not have taed? could she not have taed? could we not have taed? could you not have taed? could they not have taed?
V-ing perfect
could I not have been taing? could you not have been taing? could she not have been taing? could we not have been taing? could you not have been taing? could they not have been taing?