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