English verb conjugation
CAN BOX

Regular verb: box - boxed - boxed

Affirmation

Simple form	V-ing form
I can box you can box he can box we can box you can box they can box	I can be boxing you can be boxing he can be boxing we can be boxing you can be boxing they can be boxing
Perfect	V-ing perfect
I can have boxed you can have boxed he can have boxed we can have boxed you can have boxed they can have boxed	I can have been boxing you can have been boxing he can have been boxing we can have been boxing you can have been boxing they can have been boxing

Negation

Simple form	V-ing form
I can't box you can't box he can't box we can't box you can't box they can't box	I can't be boxing you can't be boxing he can't be boxing we can't be boxing you can't be boxing they can't be boxing
Perfect	V-ing perfect
I can't have boxed you can't have boxed he can't have boxed we can't have boxed you can't have boxed they can't have boxed	I can't have been boxing you can't have been boxing he can't have been boxing we can't have been boxing you can't have been boxing they can't have been boxing

Interrogative form

Simple form	V-ing form
can I box? can you box? can he box? can we box? can you box? can they box?	can I be boxing? can you be boxing? can he be boxing? can we be boxing? can you be boxing? can they be boxing?
Perfect	V-ing perfect
can I have boxed? can you have boxed? can he have boxed? can we have boxed? can you have boxed? can they have boxed?	can I have been boxing? can you have been boxing? can he have been boxing? can we have been boxing? can you have been boxing? can they have been boxing?

Interro-negative form

Simple form	V-ing form
can't I box? can't you box? can't he box? can't we box? can't you box? can't they box?	can't I be boxing? can't you be boxing? can't he be boxing? can't we be boxing? can't you be boxing? can't they be boxing?
Perfect	V-ing perfect
can't I have boxed? can't you have boxed? can't he have boxed? can't we have boxed? can't you have boxed? can't they have boxed?	can't I have been boxing? can't you have been boxing? can't he have been boxing? can't we have been boxing? can't you have been boxing? can't they have been boxing?