I could bop you could bop he could bop we could bop you could bop they could bop
V-ing form
I could be boping you could be boping he could be boping we could be boping you could be boping they could be boping
Perfect
I could have boped you could have boped he could have boped we could have boped you could have boped they could have boped
V-ing perfect
I could have been boping you could have been boping he could have been boping we could have been boping you could have been boping they could have been boping
Negation
Simple form
I could not bop you could not bop he could not bop we could not bop you could not bop they could not bop
V-ing form
I could not be boping you could not be boping he could not be boping we could not be boping you could not be boping they could not be boping
Perfect
I could not have boped you could not have boped he could not have boped we could not have boped you could not have boped they could not have boped
V-ing perfect
I could not have been boping you could not have been boping he could not have been boping we could not have been boping you could not have been boping they could not have been boping
Interrogative form
Simple form
could I bop? could you bop? could he bop? could we bop? could you bop? could they bop?
V-ing form
could I be boping? could you be boping? could he be boping? could we be boping? could you be boping? could they be boping?
Perfect
could I have boped? could you have boped? could he have boped? could we have boped? could you have boped? could they have boped?
V-ing perfect
could I have been boping? could you have been boping? could he have been boping? could we have been boping? could you have been boping? could they have been boping?
Interro-negative form
Simple form
could I not bop? could you not bop? could he not bop? could we not bop? could you not bop? could they not bop?
V-ing form
could I not be boping? could you not be boping? could he not be boping? could we not be boping? could you not be boping? could they not be boping?
Perfect
could I not have boped? could you not have boped? could he not have boped? could we not have boped? could you not have boped? could they not have boped?
V-ing perfect
could I not have been boping? could you not have been boping? could he not have been boping? could we not have been boping? could you not have been boping? could they not have been boping?