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