must fire
Regular verb: fire - fired- fired

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must fire
you must fire
he must fire
we must fire
you must fire
they must fire 	I must be firing
you must be firing
he must be firing
we must be firing
you must be firing
they must be firing	I must have fired
you must have fired
he must have fired
we must have fired
you must have fired
they must have fired	I must have been firing
you must have been firing
he must have been firing
we must have been firing
you must have been firing
they must have been firing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not fire
you must not fire
he must not fire
we must not fire
you must not fire
they must not fire 	I must not be firing
you must not be firing
he must not be firing
we must not be firing
you must not be firing
they must not be firing	I must not have fired
you must not have fired
he must not have fired
we must not have fired
you must not have fired
they must not have fired	I must not have been firing
you must not have been firing
he must not have been firing
we must not have been firing
you must not have been firing
they must not have been firing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I fire?
must you fire?
must he fire?
must we fire?
must you fire?
must they fire? 	must I be firing?
must you be firing?
must he be firing?
must we be firing?
must you be firing?
must they be firing? 	must I have fired?
must you have fired?
must he have fired?
must we have fired?
must you have fired?
must they have fired? 	must I have been firing?
must you have been firing?
must he have been firing?
must we have been firing?
must you have been firing?
must they have been firing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not fire?
must you not fire?
must he not fire?
must we not fire?
must you not fire?
must they not fire? 	must I not be firing?
must you not be firing?
must he not be firing?
must we not be firing?
must you not be firing?
must they not be firing? 	must I not have fired?
must you not have fired?
must he not have fired?
must we not have fired?
must you not have fired?
must they not have fired? 	must I not have been firing?
must you not have been firing?
must he not have been firing?
must we not have been firing?
must you not have been firing?
must they not have been firing?