English verb conjugation
CAN RACK

Regular verb: rack - racked - racked

Affirmation

Simple form	V-ing form
I can rack you can rack he can rack we can rack you can rack they can rack	I can be racking you can be racking he can be racking we can be racking you can be racking they can be racking
Perfect	V-ing perfect
I can have racked you can have racked he can have racked we can have racked you can have racked they can have racked	I can have been racking you can have been racking he can have been racking we can have been racking you can have been racking they can have been racking

Negation

Simple form	V-ing form
I cannot rack you cannot rack he cannot rack we cannot rack you cannot rack they cannot rack	I cannot be racking you cannot be racking he cannot be racking we cannot be racking you cannot be racking they cannot be racking
Perfect	V-ing perfect
I cannot have racked you cannot have racked he cannot have racked we cannot have racked you cannot have racked they cannot have racked	I cannot have been racking you cannot have been racking he cannot have been racking we cannot have been racking you cannot have been racking they cannot have been racking

Interrogative form

Simple form	V-ing form
can I rack? can you rack? can he rack? can we rack? can you rack? can they rack?	can I be racking? can you be racking? can he be racking? can we be racking? can you be racking? can they be racking?
Perfect	V-ing perfect
can I have racked? can you have racked? can he have racked? can we have racked? can you have racked? can they have racked?	can I have been racking? can you have been racking? can he have been racking? can we have been racking? can you have been racking? can they have been racking?

Interro-negative form

Simple form	V-ing form
can I not rack? can you not rack? can he not rack? can we not rack? can you not rack? can they not rack?	can I not be racking? can you not be racking? can he not be racking? can we not be racking? can you not be racking? can they not be racking?
Perfect	V-ing perfect
can I not have racked? can you not have racked? can he not have racked? can we not have racked? can you not have racked? can they not have racked?	can I not have been racking? can you not have been racking? can he not have been racking? can we not have been racking? can you not have been racking? can they not have been racking?