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