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