English verb conjugation
COULD CASE

Regular verb: case - cased - cased

Affirmation

Simple form	V-ing form
I could case you could case he could case we could case you could case they could case	I could be casing you could be casing he could be casing we could be casing you could be casing they could be casing
Perfect	V-ing perfect
I could have cased you could have cased he could have cased we could have cased you could have cased they could have cased	I could have been casing you could have been casing he could have been casing we could have been casing you could have been casing they could have been casing

Negation

Simple form	V-ing form
I could not case you could not case he could not case we could not case you could not case they could not case	I could not be casing you could not be casing he could not be casing we could not be casing you could not be casing they could not be casing
Perfect	V-ing perfect
I could not have cased you could not have cased he could not have cased we could not have cased you could not have cased they could not have cased	I could not have been casing you could not have been casing he could not have been casing we could not have been casing you could not have been casing they could not have been casing

Interrogative form

Simple form	V-ing form
could I case? could you case? could he case? could we case? could you case? could they case?	could I be casing? could you be casing? could he be casing? could we be casing? could you be casing? could they be casing?
Perfect	V-ing perfect
could I have cased? could you have cased? could he have cased? could we have cased? could you have cased? could they have cased?	could I have been casing? could you have been casing? could he have been casing? could we have been casing? could you have been casing? could they have been casing?

Interro-negative form

Simple form	V-ing form
could I not case? could you not case? could he not case? could we not case? could you not case? could they not case?	could I not be casing? could you not be casing? could he not be casing? could we not be casing? could you not be casing? could they not be casing?
Perfect	V-ing perfect
could I not have cased? could you not have cased? could he not have cased? could we not have cased? could you not have cased? could they not have cased?	could I not have been casing? could you not have been casing? could he not have been casing? could we not have been casing? could you not have been casing? could they not have been casing?