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 must not fight you must not fight he must not fight we must not fight you must not fight they must not fight	I must not be fighting you must not be fighting he must not be fighting we must not be fighting you must not be fighting they must not be fighting
Perfect	V-ing perfect
I must not have fought you must not have fought he must not have fought we must not have fought you must not have fought they must not have fought	I must not have been fighting you must not have been fighting he must not have been fighting we must not have been fighting you must not have been fighting they must not 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
must I not fight? must you not fight? must he not fight? must we not fight? must you not fight? must they not fight?	must I not be fighting? must you not be fighting? must he not be fighting? must we not be fighting? must you not be fighting? must they not be fighting?
Perfect	V-ing perfect
must I not have fought? must you not have fought? must he not have fought? must we not have fought? must you not have fought? must they not have fought?	must I not have been fighting? must you not have been fighting? must he not have been fighting? must we not have been fighting? must you not have been fighting? must they not have been fighting?