Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I must frighten frighten you must frighten frighten he must frighten frighten we must frighten frighten you must frighten frighten they must frighten frighten
V-ing form
I must be frighten frightening you must be frighten frightening he must be frighten frightening we must be frighten frightening you must be frighten frightening they must be frighten frightening
Perfect
I must have frighten frightened you must have frighten frightened he must have frighten frightened we must have frighten frightened you must have frighten frightened they must have frighten frightened
V-ing perfect
I must have been frighten frightening you must have been frighten frightening he must have been frighten frightening we must have been frighten frightening you must have been frighten frightening they must have been frighten frightening
Negation
Simple form
I mustn't frighten frighten you mustn't frighten frighten he mustn't frighten frighten we mustn't frighten frighten you mustn't frighten frighten they mustn't frighten frighten
V-ing form
I mustn't be frighten frightening you mustn't be frighten frightening he mustn't be frighten frightening we mustn't be frighten frightening you mustn't be frighten frightening they mustn't be frighten frightening
Perfect
I mustn't have frighten frightened you mustn't have frighten frightened he mustn't have frighten frightened we mustn't have frighten frightened you mustn't have frighten frightened they mustn't have frighten frightened
V-ing perfect
I mustn't have been frighten frightening you mustn't have been frighten frightening he mustn't have been frighten frightening we mustn't have been frighten frightening you mustn't have been frighten frightening they mustn't have been frighten frightening
Interrogative form
Simple form
must I frighten frighten? must you frighten frighten? must he frighten frighten? must we frighten frighten? must you frighten frighten? must they frighten frighten?
V-ing form
must I be frighten frightening? must you be frighten frightening? must he be frighten frightening? must we be frighten frightening? must you be frighten frightening? must they be frighten frightening?
Perfect
must I have frighten frightened? must you have frighten frightened? must he have frighten frightened? must we have frighten frightened? must you have frighten frightened? must they have frighten frightened?
V-ing perfect
must I have been frighten frightening? must you have been frighten frightening? must he have been frighten frightening? must we have been frighten frightening? must you have been frighten frightening? must they have been frighten frightening?
Interro-negative form
Simple form
mustn't I frighten frighten? mustn't you frighten frighten? mustn't he frighten frighten? mustn't we frighten frighten? mustn't you frighten frighten? mustn't they frighten frighten?
V-ing form
mustn't I be frighten frightening? mustn't you be frighten frightening? mustn't he be frighten frightening? mustn't we be frighten frightening? mustn't you be frighten frightening? mustn't they be frighten frightening?
Perfect
mustn't I have frighten frightened? mustn't you have frighten frightened? mustn't he have frighten frightened? mustn't we have frighten frightened? mustn't you have frighten frightened? mustn't they have frighten frightened?
V-ing perfect
mustn't I have been frighten frightening? mustn't you have been frighten frightening? mustn't he have been frighten frightening? mustn't we have been frighten frightening? mustn't you have been frighten frightening? mustn't they have been frighten frightening?