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