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