must subsist
Regular verb: subsist - subsisted- subsisted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must subsist
you must subsist
she must subsist
we must subsist
you must subsist
they must subsist 	I must be subsisting
you must be subsisting
she must be subsisting
we must be subsisting
you must be subsisting
they must be subsisting	I must have subsisted
you must have subsisted
she must have subsisted
we must have subsisted
you must have subsisted
they must have subsisted	I must have been subsisting
you must have been subsisting
she must have been subsisting
we must have been subsisting
you must have been subsisting
they must have been subsisting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't subsist
you mustn't subsist
she mustn't subsist
we mustn't subsist
you mustn't subsist
they mustn't subsist 	I mustn't be subsisting
you mustn't be subsisting
she mustn't be subsisting
we mustn't be subsisting
you mustn't be subsisting
they mustn't be subsisting	I mustn't have subsisted
you mustn't have subsisted
she mustn't have subsisted
we mustn't have subsisted
you mustn't have subsisted
they mustn't have subsisted	I mustn't have been subsisting
you mustn't have been subsisting
she mustn't have been subsisting
we mustn't have been subsisting
you mustn't have been subsisting
they mustn't have been subsisting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I subsist?
must you subsist?
must she subsist?
must we subsist?
must you subsist?
must they subsist? 	must I be subsisting?
must you be subsisting?
must she be subsisting?
must we be subsisting?
must you be subsisting?
must they be subsisting? 	must I have subsisted?
must you have subsisted?
must she have subsisted?
must we have subsisted?
must you have subsisted?
must they have subsisted? 	must I have been subsisting?
must you have been subsisting?
must she have been subsisting?
must we have been subsisting?
must you have been subsisting?
must they have been subsisting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I subsist?
mustn't you subsist?
mustn't she subsist?
mustn't we subsist?
mustn't you subsist?
mustn't they subsist? 	mustn't I be subsisting?
mustn't you be subsisting?
mustn't she be subsisting?
mustn't we be subsisting?
mustn't you be subsisting?
mustn't they be subsisting? 	mustn't I have subsisted?
mustn't you have subsisted?
mustn't she have subsisted?
mustn't we have subsisted?
mustn't you have subsisted?
mustn't they have subsisted? 	mustn't I have been subsisting?
mustn't you have been subsisting?
mustn't she have been subsisting?
mustn't we have been subsisting?
mustn't you have been subsisting?
mustn't they have been subsisting?