I must refit you must refit he must refit we must refit you must refit they must refit
V-ing form
I must be refitting you must be refitting he must be refitting we must be refitting you must be refitting they must be refitting
Perfect
I must have refit you must have refit he 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 he 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 he 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 he 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 he 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 he 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 he refit? must we refit? must you refit? must they refit?
V-ing form
must I be refitting? must you be refitting? must he be refitting? must we be refitting? must you be refitting? must they be refitting?
Perfect
must I have refit? must you have refit? must he 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 he 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 he 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 he 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 he 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 he have been refitting? mustn't we have been refitting? mustn't you have been refitting? mustn't they have been refitting?