I must worsen you must worsen she must worsen we must worsen you must worsen they must worsen
V-ing form
I must be worsening you must be worsening she must be worsening we must be worsening you must be worsening they must be worsening
Perfect
I must have worsened you must have worsened she must have worsened we must have worsened you must have worsened they must have worsened
V-ing perfect
I must have been worsening you must have been worsening she must have been worsening we must have been worsening you must have been worsening they must have been worsening
Negation
Simple form
I mustn't worsen you mustn't worsen she mustn't worsen we mustn't worsen you mustn't worsen they mustn't worsen
V-ing form
I mustn't be worsening you mustn't be worsening she mustn't be worsening we mustn't be worsening you mustn't be worsening they mustn't be worsening
Perfect
I mustn't have worsened you mustn't have worsened she mustn't have worsened we mustn't have worsened you mustn't have worsened they mustn't have worsened
V-ing perfect
I mustn't have been worsening you mustn't have been worsening she mustn't have been worsening we mustn't have been worsening you mustn't have been worsening they mustn't have been worsening
Interrogative form
Simple form
must I worsen? must you worsen? must she worsen? must we worsen? must you worsen? must they worsen?
V-ing form
must I be worsening? must you be worsening? must she be worsening? must we be worsening? must you be worsening? must they be worsening?
Perfect
must I have worsened? must you have worsened? must she have worsened? must we have worsened? must you have worsened? must they have worsened?
V-ing perfect
must I have been worsening? must you have been worsening? must she have been worsening? must we have been worsening? must you have been worsening? must they have been worsening?
Interro-negative form
Simple form
mustn't I worsen? mustn't you worsen? mustn't she worsen? mustn't we worsen? mustn't you worsen? mustn't they worsen?
V-ing form
mustn't I be worsening? mustn't you be worsening? mustn't she be worsening? mustn't we be worsening? mustn't you be worsening? mustn't they be worsening?
Perfect
mustn't I have worsened? mustn't you have worsened? mustn't she have worsened? mustn't we have worsened? mustn't you have worsened? mustn't they have worsened?
V-ing perfect
mustn't I have been worsening? mustn't you have been worsening? mustn't she have been worsening? mustn't we have been worsening? mustn't you have been worsening? mustn't they have been worsening?