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 must not widen you must not widen he must not widen we must not widen you must not widen they must not widen
V-ing form
I must not be widening you must not be widening he must not be widening we must not be widening you must not be widening they must not be widening
Perfect
I must not have widened you must not have widened he must not have widened we must not have widened you must not have widened they must not have widened
V-ing perfect
I must not have been widening you must not have been widening he must not have been widening we must not have been widening you must not have been widening they must not 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
must I not widen? must you not widen? must he not widen? must we not widen? must you not widen? must they not widen?
V-ing form
must I not be widening? must you not be widening? must he not be widening? must we not be widening? must you not be widening? must they not be widening?
Perfect
must I not have widened? must you not have widened? must he not have widened? must we not have widened? must you not have widened? must they not have widened?
V-ing perfect
must I not have been widening? must you not have been widening? must he not have been widening? must we not have been widening? must you not have been widening? must they not have been widening?