I can button you can button he can button we can button you can button they can button
V-ing form
I can be buttoning you can be buttoning he can be buttoning we can be buttoning you can be buttoning they can be buttoning
Perfect
I can have buttoned you can have buttoned he can have buttoned we can have buttoned you can have buttoned they can have buttoned
V-ing perfect
I can have been buttoning you can have been buttoning he can have been buttoning we can have been buttoning you can have been buttoning they can have been buttoning
Negation
Simple form
I can't button you can't button he can't button we can't button you can't button they can't button
V-ing form
I can't be buttoning you can't be buttoning he can't be buttoning we can't be buttoning you can't be buttoning they can't be buttoning
Perfect
I can't have buttoned you can't have buttoned he can't have buttoned we can't have buttoned you can't have buttoned they can't have buttoned
V-ing perfect
I can't have been buttoning you can't have been buttoning he can't have been buttoning we can't have been buttoning you can't have been buttoning they can't have been buttoning
Interrogative form
Simple form
can I button? can you button? can he button? can we button? can you button? can they button?
V-ing form
can I be buttoning? can you be buttoning? can he be buttoning? can we be buttoning? can you be buttoning? can they be buttoning?
Perfect
can I have buttoned? can you have buttoned? can he have buttoned? can we have buttoned? can you have buttoned? can they have buttoned?
V-ing perfect
can I have been buttoning? can you have been buttoning? can he have been buttoning? can we have been buttoning? can you have been buttoning? can they have been buttoning?
Interro-negative form
Simple form
can't I button? can't you button? can't he button? can't we button? can't you button? can't they button?
V-ing form
can't I be buttoning? can't you be buttoning? can't he be buttoning? can't we be buttoning? can't you be buttoning? can't they be buttoning?
Perfect
can't I have buttoned? can't you have buttoned? can't he have buttoned? can't we have buttoned? can't you have buttoned? can't they have buttoned?
V-ing perfect
can't I have been buttoning? can't you have been buttoning? can't he have been buttoning? can't we have been buttoning? can't you have been buttoning? can't they have been buttoning?