I could leak you could leak he could leak we could leak you could leak they could leak
V-ing form
I could be leaking you could be leaking he could be leaking we could be leaking you could be leaking they could be leaking
Perfect
I could have leaked you could have leaked he could have leaked we could have leaked you could have leaked they could have leaked
V-ing perfect
I could have been leaking you could have been leaking he could have been leaking we could have been leaking you could have been leaking they could have been leaking
Negation
Simple form
I could not leak you could not leak he could not leak we could not leak you could not leak they could not leak
V-ing form
I could not be leaking you could not be leaking he could not be leaking we could not be leaking you could not be leaking they could not be leaking
Perfect
I could not have leaked you could not have leaked he could not have leaked we could not have leaked you could not have leaked they could not have leaked
V-ing perfect
I could not have been leaking you could not have been leaking he could not have been leaking we could not have been leaking you could not have been leaking they could not have been leaking
Interrogative form
Simple form
could I leak? could you leak? could he leak? could we leak? could you leak? could they leak?
V-ing form
could I be leaking? could you be leaking? could he be leaking? could we be leaking? could you be leaking? could they be leaking?
Perfect
could I have leaked? could you have leaked? could he have leaked? could we have leaked? could you have leaked? could they have leaked?
V-ing perfect
could I have been leaking? could you have been leaking? could he have been leaking? could we have been leaking? could you have been leaking? could they have been leaking?
Interro-negative form
Simple form
could I not leak? could you not leak? could he not leak? could we not leak? could you not leak? could they not leak?
V-ing form
could I not be leaking? could you not be leaking? could he not be leaking? could we not be leaking? could you not be leaking? could they not be leaking?
Perfect
could I not have leaked? could you not have leaked? could he not have leaked? could we not have leaked? could you not have leaked? could they not have leaked?
V-ing perfect
could I not have been leaking? could you not have been leaking? could he not have been leaking? could we not have been leaking? could you not have been leaking? could they not have been leaking?