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