I must chap you must chap he must chap we must chap you must chap they must chap
V-ing form
I must be chapping you must be chapping he must be chapping we must be chapping you must be chapping they must be chapping
Perfect
I must have chapped you must have chapped he 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 he must have been chapping we must have been chapping you must have been chapping they must have been chapping
Negation
Simple form
I mustn't chap you mustn't chap he mustn't chap we mustn't chap you mustn't chap they mustn't chap
V-ing form
I mustn't be chapping you mustn't be chapping he mustn't be chapping we mustn't be chapping you mustn't be chapping they mustn't be chapping
Perfect
I mustn't have chapped you mustn't have chapped he mustn't have chapped we mustn't have chapped you mustn't have chapped they mustn't have chapped
V-ing perfect
I mustn't have been chapping you mustn't have been chapping he mustn't have been chapping we mustn't have been chapping you mustn't have been chapping they mustn't have been chapping
Interrogative form
Simple form
must I chap? must you chap? must he chap? must we chap? must you chap? must they chap?
V-ing form
must I be chapping? must you be chapping? must he be chapping? must we be chapping? must you be chapping? must they be chapping?
Perfect
must I have chapped? must you have chapped? must he 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 he have been chapping? must we have been chapping? must you have been chapping? must they have been chapping?
Interro-negative form
Simple form
mustn't I chap? mustn't you chap? mustn't he chap? mustn't we chap? mustn't you chap? mustn't they chap?
V-ing form
mustn't I be chapping? mustn't you be chapping? mustn't he be chapping? mustn't we be chapping? mustn't you be chapping? mustn't they be chapping?
Perfect
mustn't I have chapped? mustn't you have chapped? mustn't he have chapped? mustn't we have chapped? mustn't you have chapped? mustn't they have chapped?
V-ing perfect
mustn't I have been chapping? mustn't you have been chapping? mustn't he have been chapping? mustn't we have been chapping? mustn't you have been chapping? mustn't they have been chapping?