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