I must chap you must chap she must chap we must chap you must chap they must chap
V-ing form
I must be chapping you must be chapping she must be chapping we must be chapping you must be chapping they must be chapping
Perfect
I must have chapped you must have chapped she must have chapped we must have chapped you must have chapped they must have chapped
V-ing perfect
I must have been chapping you must have been chapping she must have been chapping we must have been chapping you must have been chapping they must have been chapping
Negation
Simple form
I must not chap you must not chap she must not chap we must not chap you must not chap they must not chap
V-ing form
I must not be chapping you must not be chapping she must not be chapping we must not be chapping you must not be chapping they must not be chapping
Perfect
I must not have chapped you must not have chapped she must not have chapped we must not have chapped you must not have chapped they must not have chapped
V-ing perfect
I must not have been chapping you must not have been chapping she must not have been chapping we must not have been chapping you must not have been chapping they must not have been chapping
Interrogative form
Simple form
must I chap? must you chap? must she chap? must we chap? must you chap? must they chap?
V-ing form
must I be chapping? must you be chapping? must she be chapping? must we be chapping? must you be chapping? must they be chapping?
Perfect
must I have chapped? must you have chapped? must she have chapped? must we have chapped? must you have chapped? must they have chapped?
V-ing perfect
must I have been chapping? must you have been chapping? must she have been chapping? must we have been chapping? must you have been chapping? must they have been chapping?
Interro-negative form
Simple form
must I not chap? must you not chap? must she not chap? must we not chap? must you not chap? must they not chap?
V-ing form
must I not be chapping? must you not be chapping? must she not be chapping? must we not be chapping? must you not be chapping? must they not be chapping?
Perfect
must I not have chapped? must you not have chapped? must she not have chapped? must we not have chapped? must you not have chapped? must they not have chapped?
V-ing perfect
must I not have been chapping? must you not have been chapping? must she not have been chapping? must we not have been chapping? must you not have been chapping? must they not have been chapping?