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