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