I must liven you must liven she must liven we must liven you must liven they must liven
V-ing form
I must be livening you must be livening she must be livening we must be livening you must be livening they must be livening
Perfect
I must have livened you must have livened she 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 she 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 she 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 she 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 she 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 she 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 she liven? must we liven? must you liven? must they liven?
V-ing form
must I be livening? must you be livening? must she be livening? must we be livening? must you be livening? must they be livening?
Perfect
must I have livened? must you have livened? must she 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 she 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 she 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 she 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 she 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 she have been livening? mustn't we have been livening? mustn't you have been livening? mustn't they have been livening?