I must refuse you must refuse she must refuse we must refuse you must refuse they must refuse
V-ing form
I must be refusing you must be refusing she must be refusing we must be refusing you must be refusing they must be refusing
Perfect
I must have refused you must have refused she 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 she 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 she 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 she 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 she 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 she 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 she refuse? must we refuse? must you refuse? must they refuse?
V-ing form
must I be refusing? must you be refusing? must she be refusing? must we be refusing? must you be refusing? must they be refusing?
Perfect
must I have refused? must you have refused? must she 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 she 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 she 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 she 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 she 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 she have been refusing? mustn't we have been refusing? mustn't you have been refusing? mustn't they have been refusing?