English verb conjugation
CAN SPAR

Regular verb: spar - sparred - sparred

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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