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