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 can't swap you can't swap he can't swap we can't swap you can't swap they can't swap
V-ing form
I can't be swaping you can't be swaping he can't be swaping we can't be swaping you can't be swaping they can't be swaping
Perfect
I can't have swaped you can't have swaped he can't have swaped we can't have swaped you can't have swaped they can't have swaped
V-ing perfect
I can't have been swaping you can't have been swaping he can't have been swaping we can't have been swaping you can't have been swaping they can't 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't I swap? can't you swap? can't he swap? can't we swap? can't you swap? can't they swap?
V-ing form
can't I be swaping? can't you be swaping? can't he be swaping? can't we be swaping? can't you be swaping? can't they be swaping?
Perfect
can't I have swaped? can't you have swaped? can't he have swaped? can't we have swaped? can't you have swaped? can't they have swaped?
V-ing perfect
can't I have been swaping? can't you have been swaping? can't he have been swaping? can't we have been swaping? can't you have been swaping? can't they have been swaping?