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