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