English verb conjugation
CAN BUTTON

Regular verb: button - buttoned - buttoned

Affirmation

Simple form	V-ing form
I can button you can button he can button we can button you can button they can button	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	V-ing 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	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	V-ing 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	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	V-ing 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	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	V-ing form
can I button? can you button? can he button? can we button? can you button? can they button?	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	V-ing 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?	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	V-ing 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?	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	V-ing 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?	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?