must extinguish
Regular verb: extinguish - extinguished- extinguished

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must extinguish
you must extinguish
she must extinguish
we must extinguish
you must extinguish
they must extinguish 	I must be extinguishing
you must be extinguishing
she must be extinguishing
we must be extinguishing
you must be extinguishing
they must be extinguishing	I must have extinguished
you must have extinguished
she 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
she 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
she 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
she 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
she 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
she 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 she extinguish?
must we extinguish?
must you extinguish?
must they extinguish? 	must I be extinguishing?
must you be extinguishing?
must she be extinguishing?
must we be extinguishing?
must you be extinguishing?
must they be extinguishing? 	must I have extinguished?
must you have extinguished?
must she 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 she 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 she 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 she 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 she 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 she have been extinguishing?
mustn't we have been extinguishing?
mustn't you have been extinguishing?
mustn't they have been extinguishing?