could kitten
Regular verb: kitten - kittened- kittened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could kitten
you could kitten
she could kitten
we could kitten
you could kitten
they could kitten 	I could be kittening
you could be kittening
she could be kittening
we could be kittening
you could be kittening
they could be kittening	I could have kittened
you could have kittened
she could have kittened
we could have kittened
you could have kittened
they could have kittened	I could have been kittening
you could have been kittening
she could have been kittening
we could have been kittening
you could have been kittening
they could have been kittening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not kitten
you could not kitten
she could not kitten
we could not kitten
you could not kitten
they could not kitten 	I could not be kittening
you could not be kittening
she could not be kittening
we could not be kittening
you could not be kittening
they could not be kittening	I could not have kittened
you could not have kittened
she could not have kittened
we could not have kittened
you could not have kittened
they could not have kittened	I could not have been kittening
you could not have been kittening
she could not have been kittening
we could not have been kittening
you could not have been kittening
they could not have been kittening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I kitten?
could you kitten?
could she kitten?
could we kitten?
could you kitten?
could they kitten? 	could I be kittening?
could you be kittening?
could she be kittening?
could we be kittening?
could you be kittening?
could they be kittening? 	could I have kittened?
could you have kittened?
could she have kittened?
could we have kittened?
could you have kittened?
could they have kittened? 	could I have been kittening?
could you have been kittening?
could she have been kittening?
could we have been kittening?
could you have been kittening?
could they have been kittening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not kitten?
could you not kitten?
could she not kitten?
could we not kitten?
could you not kitten?
could they not kitten? 	could I not be kittening?
could you not be kittening?
could she not be kittening?
could we not be kittening?
could you not be kittening?
could they not be kittening? 	could I not have kittened?
could you not have kittened?
could she not have kittened?
could we not have kittened?
could you not have kittened?
could they not have kittened? 	could I not have been kittening?
could you not have been kittening?
could she not have been kittening?
could we not have been kittening?
could you not have been kittening?
could they not have been kittening?