I can swap you can swap he can swap we can swap you can swap they can swap
V-ing form
I can be swaping you can be swaping he can be swaping we can be swaping you can be swaping they can be swaping
Perfect
I can have swaped you can have swaped he can have swaped we can have swaped you can have swaped they can have swaped
V-ing perfect
I can have been swaping you can have been swaping he can have been swaping we can have been swaping you can have been swaping they can have been swaping
Negation
Simple form
I cannot swap you cannot swap he cannot swap we cannot swap you cannot swap they cannot swap
V-ing form
I cannot be swaping you cannot be swaping he cannot be swaping we cannot be swaping you cannot be swaping they cannot be swaping
Perfect
I cannot have swaped you cannot have swaped he cannot have swaped we cannot have swaped you cannot have swaped they cannot have swaped
V-ing perfect
I cannot have been swaping you cannot have been swaping he cannot have been swaping we cannot have been swaping you cannot have been swaping they cannot have been swaping
Interrogative form
Simple form
can I swap? can you swap? can he swap? can we swap? can you swap? can they swap?
V-ing form
can I be swaping? can you be swaping? can he be swaping? can we be swaping? can you be swaping? can they be swaping?
Perfect
can I have swaped? can you have swaped? can he have swaped? can we have swaped? can you have swaped? can they have swaped?
V-ing perfect
can I have been swaping? can you have been swaping? can he have been swaping? can we have been swaping? can you have been swaping? can they have been swaping?
Interro-negative form
Simple form
can I not swap? can you not swap? can he not swap? can we not swap? can you not swap? can they not swap?
V-ing form
can I not be swaping? can you not be swaping? can he not be swaping? can we not be swaping? can you not be swaping? can they not be swaping?
Perfect
can I not have swaped? can you not have swaped? can he not have swaped? can we not have swaped? can you not have swaped? can they not have swaped?
V-ing perfect
can I not have been swaping? can you not have been swaping? can he not have been swaping? can we not have been swaping? can you not have been swaping? can they not have been swaping?