English verb conjugation
COULD CALL

Regular verb: call - called - called

Affirmation

Simple form	V-ing form
I could call you could call he could call we could call you could call they could call	I could be calling you could be calling he could be calling we could be calling you could be calling they could be calling
Perfect	V-ing perfect
I could have called you could have called he could have called we could have called you could have called they could have called	I could have been calling you could have been calling he could have been calling we could have been calling you could have been calling they could have been calling

Negation

Simple form	V-ing form
I could not call you could not call he could not call we could not call you could not call they could not call	I could not be calling you could not be calling he could not be calling we could not be calling you could not be calling they could not be calling
Perfect	V-ing perfect
I could not have called you could not have called he could not have called we could not have called you could not have called they could not have called	I could not have been calling you could not have been calling he could not have been calling we could not have been calling you could not have been calling they could not have been calling

Interrogative form

Simple form	V-ing form
could I call? could you call? could he call? could we call? could you call? could they call?	could I be calling? could you be calling? could he be calling? could we be calling? could you be calling? could they be calling?
Perfect	V-ing perfect
could I have called? could you have called? could he have called? could we have called? could you have called? could they have called?	could I have been calling? could you have been calling? could he have been calling? could we have been calling? could you have been calling? could they have been calling?

Interro-negative form

Simple form	V-ing form
could I not call? could you not call? could he not call? could we not call? could you not call? could they not call?	could I not be calling? could you not be calling? could he not be calling? could we not be calling? could you not be calling? could they not be calling?
Perfect	V-ing perfect
could I not have called? could you not have called? could he not have called? could we not have called? could you not have called? could they not have called?	could I not have been calling? could you not have been calling? could he not have been calling? could we not have been calling? could you not have been calling? could they not have been calling?