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 can't spar you can't spar he can't spar we can't spar you can't spar they can't spar	I can't be sparring you can't be sparring he can't be sparring we can't be sparring you can't be sparring they can't be sparring
Perfect	V-ing perfect
I can't have sparred you can't have sparred he can't have sparred we can't have sparred you can't have sparred they can't have sparred	I can't have been sparring you can't have been sparring he can't have been sparring we can't have been sparring you can't have been sparring they can't 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't I spar? can't you spar? can't he spar? can't we spar? can't you spar? can't they spar?	can't I be sparring? can't you be sparring? can't he be sparring? can't we be sparring? can't you be sparring? can't they be sparring?
Perfect	V-ing perfect
can't I have sparred? can't you have sparred? can't he have sparred? can't we have sparred? can't you have sparred? can't they have sparred?	can't I have been sparring? can't you have been sparring? can't he have been sparring? can't we have been sparring? can't you have been sparring? can't they have been sparring?