English verb conjugation
CAN STAFF

Regular verb: staff - staffed - staffed

Affirmation

Simple form	V-ing form
I can staff you can staff he can staff we can staff you can staff they can staff	I can be staffing you can be staffing he can be staffing we can be staffing you can be staffing they can be staffing
Perfect	V-ing perfect
I can have staffed you can have staffed he can have staffed we can have staffed you can have staffed they can have staffed	I can have been staffing you can have been staffing he can have been staffing we can have been staffing you can have been staffing they can have been staffing

Negation

Simple form	V-ing form
I cannot staff you cannot staff he cannot staff we cannot staff you cannot staff they cannot staff	I cannot be staffing you cannot be staffing he cannot be staffing we cannot be staffing you cannot be staffing they cannot be staffing
Perfect	V-ing perfect
I cannot have staffed you cannot have staffed he cannot have staffed we cannot have staffed you cannot have staffed they cannot have staffed	I cannot have been staffing you cannot have been staffing he cannot have been staffing we cannot have been staffing you cannot have been staffing they cannot have been staffing

Interrogative form

Simple form	V-ing form
can I staff? can you staff? can he staff? can we staff? can you staff? can they staff?	can I be staffing? can you be staffing? can he be staffing? can we be staffing? can you be staffing? can they be staffing?
Perfect	V-ing perfect
can I have staffed? can you have staffed? can he have staffed? can we have staffed? can you have staffed? can they have staffed?	can I have been staffing? can you have been staffing? can he have been staffing? can we have been staffing? can you have been staffing? can they have been staffing?

Interro-negative form

Simple form	V-ing form
can I not staff? can you not staff? can he not staff? can we not staff? can you not staff? can they not staff?	can I not be staffing? can you not be staffing? can he not be staffing? can we not be staffing? can you not be staffing? can they not be staffing?
Perfect	V-ing perfect
can I not have staffed? can you not have staffed? can he not have staffed? can we not have staffed? can you not have staffed? can they not have staffed?	can I not have been staffing? can you not have been staffing? can he not have been staffing? can we not have been staffing? can you not have been staffing? can they not have been staffing?