I can staple you can staple he can staple we can staple you can staple they can staple
V-ing form
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
I can have stapled you can have stapled he can have stapled we can have stapled you can have stapled they can have stapled
V-ing perfect
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
I cannot staple you cannot staple he cannot staple we cannot staple you cannot staple they cannot staple
V-ing form
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
I cannot have stapled you cannot have stapled he cannot have stapled we cannot have stapled you cannot have stapled they cannot have stapled
V-ing perfect
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
can I staple? can you staple? can he staple? can we staple? can you staple? can they staple?
V-ing form
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
can I have stapled? can you have stapled? can he have stapled? can we have stapled? can you have stapled? can they have stapled?
V-ing perfect
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
can I not staple? can you not staple? can he not staple? can we not staple? can you not staple? can they not staple?
V-ing form
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
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?
V-ing perfect
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?