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