English verb conjugation
COULD SPAR

Regular verb: spar - sparred - sparred

Affirmation

Simple form	V-ing form
I could spar you could spar he could spar we could spar you could spar they could spar	I could be sparring you could be sparring he could be sparring we could be sparring you could be sparring they could be sparring
Perfect	V-ing perfect
I could have sparred you could have sparred he could have sparred we could have sparred you could have sparred they could have sparred	I could have been sparring you could have been sparring he could have been sparring we could have been sparring you could have been sparring they could have been sparring

Negation

Simple form	V-ing form
I could not spar you could not spar he could not spar we could not spar you could not spar they could not spar	I could not be sparring you could not be sparring he could not be sparring we could not be sparring you could not be sparring they could not be sparring
Perfect	V-ing perfect
I could not have sparred you could not have sparred he could not have sparred we could not have sparred you could not have sparred they could not have sparred	I could not have been sparring you could not have been sparring he could not have been sparring we could not have been sparring you could not have been sparring they could not have been sparring

Interrogative form

Simple form	V-ing form
could I spar? could you spar? could he spar? could we spar? could you spar? could they spar?	could I be sparring? could you be sparring? could he be sparring? could we be sparring? could you be sparring? could they be sparring?
Perfect	V-ing perfect
could I have sparred? could you have sparred? could he have sparred? could we have sparred? could you have sparred? could they have sparred?	could I have been sparring? could you have been sparring? could he have been sparring? could we have been sparring? could you have been sparring? could they have been sparring?

Interro-negative form

Simple form	V-ing form
could I not spar? could you not spar? could he not spar? could we not spar? could you not spar? could they not spar?	could I not be sparring? could you not be sparring? could he not be sparring? could we not be sparring? could you not be sparring? could they not be sparring?
Perfect	V-ing perfect
could I not have sparred? could you not have sparred? could he not have sparred? could we not have sparred? could you not have sparred? could they not have sparred?	could I not have been sparring? could you not have been sparring? could he not have been sparring? could we not have been sparring? could you not have been sparring? could they not have been sparring?