English verb conjugation
CAN FLATTEN

Regular verb: flatten - flattened - flattened

Affirmation

Simple form	V-ing form
I can flatten you can flatten he can flatten we can flatten you can flatten they can flatten	I can be flattening you can be flattening he can be flattening we can be flattening you can be flattening they can be flattening
Perfect	V-ing perfect
I can have flattened you can have flattened he can have flattened we can have flattened you can have flattened they can have flattened	I can have been flattening you can have been flattening he can have been flattening we can have been flattening you can have been flattening they can have been flattening

Negation

Simple form	V-ing form
I cannot flatten you cannot flatten he cannot flatten we cannot flatten you cannot flatten they cannot flatten	I cannot be flattening you cannot be flattening he cannot be flattening we cannot be flattening you cannot be flattening they cannot be flattening
Perfect	V-ing perfect
I cannot have flattened you cannot have flattened he cannot have flattened we cannot have flattened you cannot have flattened they cannot have flattened	I cannot have been flattening you cannot have been flattening he cannot have been flattening we cannot have been flattening you cannot have been flattening they cannot have been flattening

Interrogative form

Simple form	V-ing form
can I flatten? can you flatten? can he flatten? can we flatten? can you flatten? can they flatten?	can I be flattening? can you be flattening? can he be flattening? can we be flattening? can you be flattening? can they be flattening?
Perfect	V-ing perfect
can I have flattened? can you have flattened? can he have flattened? can we have flattened? can you have flattened? can they have flattened?	can I have been flattening? can you have been flattening? can he have been flattening? can we have been flattening? can you have been flattening? can they have been flattening?

Interro-negative form

Simple form	V-ing form
can I not flatten? can you not flatten? can he not flatten? can we not flatten? can you not flatten? can they not flatten?	can I not be flattening? can you not be flattening? can he not be flattening? can we not be flattening? can you not be flattening? can they not be flattening?
Perfect	V-ing perfect
can I not have flattened? can you not have flattened? can he not have flattened? can we not have flattened? can you not have flattened? can they not have flattened?	can I not have been flattening? can you not have been flattening? can he not have been flattening? can we not have been flattening? can you not have been flattening? can they not have been flattening?