English verb conjugation
CAN STAPLE

Regular verb: staple - stapled - stapled

Affirmation

Simple form	V-ing form
I can staple you can staple he can staple we can staple you can staple they can staple	I can be stapling you can be stapling he can be stapling we can be stapling you can be stapling they can be stapling
Perfect	V-ing perfect
I can have stapled you can have stapled he can have stapled we can have stapled you can have stapled they can have stapled	I can have been stapling you can have been stapling he can have been stapling we can have been stapling you can have been stapling they can have been stapling

Negation

Simple form	V-ing form
I cannot staple you cannot staple he cannot staple we cannot staple you cannot staple they cannot staple	I cannot be stapling you cannot be stapling he cannot be stapling we cannot be stapling you cannot be stapling they cannot be stapling
Perfect	V-ing perfect
I cannot have stapled you cannot have stapled he cannot have stapled we cannot have stapled you cannot have stapled they cannot have stapled	I cannot have been stapling you cannot have been stapling he cannot have been stapling we cannot have been stapling you cannot have been stapling they cannot have been stapling

Interrogative form

Simple form	V-ing form
can I staple? can you staple? can he staple? can we staple? can you staple? can they staple?	can I be stapling? can you be stapling? can he be stapling? can we be stapling? can you be stapling? can they be stapling?
Perfect	V-ing perfect
can I have stapled? can you have stapled? can he have stapled? can we have stapled? can you have stapled? can they have stapled?	can I have been stapling? can you have been stapling? can he have been stapling? can we have been stapling? can you have been stapling? can they have been stapling?

Interro-negative form

Simple form	V-ing form
can I not staple? can you not staple? can he not staple? can we not staple? can you not staple? can they not staple?	can I not be stapling? can you not be stapling? can he not be stapling? can we not be stapling? can you not be stapling? can they not be stapling?
Perfect	V-ing perfect
can I not have stapled? can you not have stapled? can he not have stapled? can we not have stapled? can you not have stapled? can they not have stapled?	can I not have been stapling? can you not have been stapling? can he not have been stapling? can we not have been stapling? can you not have been stapling? can they not have been stapling?