English verb conjugation
COULD SUE

Regular verb: sue - sued - sued

Affirmation

Simple form	V-ing form
I could sue you could sue he could sue we could sue you could sue they could sue	I could be suing you could be suing he could be suing we could be suing you could be suing they could be suing
Perfect	V-ing perfect
I could have sued you could have sued he could have sued we could have sued you could have sued they could have sued	I could have been suing you could have been suing he could have been suing we could have been suing you could have been suing they could have been suing

Negation

Simple form	V-ing form
I could not sue you could not sue he could not sue we could not sue you could not sue they could not sue	I could not be suing you could not be suing he could not be suing we could not be suing you could not be suing they could not be suing
Perfect	V-ing perfect
I could not have sued you could not have sued he could not have sued we could not have sued you could not have sued they could not have sued	I could not have been suing you could not have been suing he could not have been suing we could not have been suing you could not have been suing they could not have been suing

Interrogative form

Simple form	V-ing form
could I sue? could you sue? could he sue? could we sue? could you sue? could they sue?	could I be suing? could you be suing? could he be suing? could we be suing? could you be suing? could they be suing?
Perfect	V-ing perfect
could I have sued? could you have sued? could he have sued? could we have sued? could you have sued? could they have sued?	could I have been suing? could you have been suing? could he have been suing? could we have been suing? could you have been suing? could they have been suing?

Interro-negative form

Simple form	V-ing form
could I not sue? could you not sue? could he not sue? could we not sue? could you not sue? could they not sue?	could I not be suing? could you not be suing? could he not be suing? could we not be suing? could you not be suing? could they not be suing?
Perfect	V-ing perfect
could I not have sued? could you not have sued? could he not have sued? could we not have sued? could you not have sued? could they not have sued?	could I not have been suing? could you not have been suing? could he not have been suing? could we not have been suing? could you not have been suing? could they not have been suing?