English verb conjugation
COULD CALL

Regular verb: call - called - called

Affirmation

Simple form	V-ing form
I could call you could call she could call we could call you could call they could call	I could be calling you could be calling she 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 she 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 she 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 couldn't call you couldn't call she couldn't call we couldn't call you couldn't call they couldn't call	I couldn't be calling you couldn't be calling she couldn't be calling we couldn't be calling you couldn't be calling they couldn't be calling
Perfect	V-ing perfect
I couldn't have called you couldn't have called she couldn't have called we couldn't have called you couldn't have called they couldn't have called	I couldn't have been calling you couldn't have been calling she couldn't have been calling we couldn't have been calling you couldn't have been calling they couldn't have been calling

Interrogative form

Simple form	V-ing form
could I call? could you call? could she call? could we call? could you call? could they call?	could I be calling? could you be calling? could she 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 she 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 she 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
couldn't I call? couldn't you call? couldn't she call? couldn't we call? couldn't you call? couldn't they call?	couldn't I be calling? couldn't you be calling? couldn't she be calling? couldn't we be calling? couldn't you be calling? couldn't they be calling?
Perfect	V-ing perfect
couldn't I have called? couldn't you have called? couldn't she have called? couldn't we have called? couldn't you have called? couldn't they have called?	couldn't I have been calling? couldn't you have been calling? couldn't she have been calling? couldn't we have been calling? couldn't you have been calling? couldn't they have been calling?