English verb conjugation
MUST FIGHT

Irregular verb: fight - fought - fought

Affirmation

Simple form	V-ing form
I must fight you must fight he must fight we must fight you must fight they must fight	I must be fighting you must be fighting he must be fighting we must be fighting you must be fighting they must be fighting
Perfect	V-ing perfect
I must have fought you must have fought he must have fought we must have fought you must have fought they must have fought	I must have been fighting you must have been fighting he must have been fighting we must have been fighting you must have been fighting they must have been fighting

Negation

Simple form	V-ing form
I mustn't fight you mustn't fight he mustn't fight we mustn't fight you mustn't fight they mustn't fight	I mustn't be fighting you mustn't be fighting he mustn't be fighting we mustn't be fighting you mustn't be fighting they mustn't be fighting
Perfect	V-ing perfect
I mustn't have fought you mustn't have fought he mustn't have fought we mustn't have fought you mustn't have fought they mustn't have fought	I mustn't have been fighting you mustn't have been fighting he mustn't have been fighting we mustn't have been fighting you mustn't have been fighting they mustn't have been fighting

Interrogative form

Simple form	V-ing form
must I fight? must you fight? must he fight? must we fight? must you fight? must they fight?	must I be fighting? must you be fighting? must he be fighting? must we be fighting? must you be fighting? must they be fighting?
Perfect	V-ing perfect
must I have fought? must you have fought? must he have fought? must we have fought? must you have fought? must they have fought?	must I have been fighting? must you have been fighting? must he have been fighting? must we have been fighting? must you have been fighting? must they have been fighting?

Interro-negative form

Simple form	V-ing form
mustn't I fight? mustn't you fight? mustn't he fight? mustn't we fight? mustn't you fight? mustn't they fight?	mustn't I be fighting? mustn't you be fighting? mustn't he be fighting? mustn't we be fighting? mustn't you be fighting? mustn't they be fighting?
Perfect	V-ing perfect
mustn't I have fought? mustn't you have fought? mustn't he have fought? mustn't we have fought? mustn't you have fought? mustn't they have fought?	mustn't I have been fighting? mustn't you have been fighting? mustn't he have been fighting? mustn't we have been fighting? mustn't you have been fighting? mustn't they have been fighting?