must extinguish
Regular verb: extinguish - extinguished- extinguished

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must extinguish
you must extinguish
he must extinguish
we must extinguish
you must extinguish
they must extinguish 	I must be extinguishing
you must be extinguishing
he must be extinguishing
we must be extinguishing
you must be extinguishing
they must be extinguishing	I must have extinguished
you must have extinguished
he must have extinguished
we must have extinguished
you must have extinguished
they must have extinguished	I must have been extinguishing
you must have been extinguishing
he must have been extinguishing
we must have been extinguishing
you must have been extinguishing
they must have been extinguishing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't extinguish
you mustn't extinguish
he mustn't extinguish
we mustn't extinguish
you mustn't extinguish
they mustn't extinguish 	I mustn't be extinguishing
you mustn't be extinguishing
he mustn't be extinguishing
we mustn't be extinguishing
you mustn't be extinguishing
they mustn't be extinguishing	I mustn't have extinguished
you mustn't have extinguished
he mustn't have extinguished
we mustn't have extinguished
you mustn't have extinguished
they mustn't have extinguished	I mustn't have been extinguishing
you mustn't have been extinguishing
he mustn't have been extinguishing
we mustn't have been extinguishing
you mustn't have been extinguishing
they mustn't have been extinguishing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I extinguish?
must you extinguish?
must he extinguish?
must we extinguish?
must you extinguish?
must they extinguish? 	must I be extinguishing?
must you be extinguishing?
must he be extinguishing?
must we be extinguishing?
must you be extinguishing?
must they be extinguishing? 	must I have extinguished?
must you have extinguished?
must he have extinguished?
must we have extinguished?
must you have extinguished?
must they have extinguished? 	must I have been extinguishing?
must you have been extinguishing?
must he have been extinguishing?
must we have been extinguishing?
must you have been extinguishing?
must they have been extinguishing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I extinguish?
mustn't you extinguish?
mustn't he extinguish?
mustn't we extinguish?
mustn't you extinguish?
mustn't they extinguish? 	mustn't I be extinguishing?
mustn't you be extinguishing?
mustn't he be extinguishing?
mustn't we be extinguishing?
mustn't you be extinguishing?
mustn't they be extinguishing? 	mustn't I have extinguished?
mustn't you have extinguished?
mustn't he have extinguished?
mustn't we have extinguished?
mustn't you have extinguished?
mustn't they have extinguished? 	mustn't I have been extinguishing?
mustn't you have been extinguishing?
mustn't he have been extinguishing?
mustn't we have been extinguishing?
mustn't you have been extinguishing?
mustn't they have been extinguishing?