must desist
Regular verb: desist - desisted- desisted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must desist
you must desist
he must desist
we must desist
you must desist
they must desist 	I must be desisting
you must be desisting
he must be desisting
we must be desisting
you must be desisting
they must be desisting	I must have desisted
you must have desisted
he must have desisted
we must have desisted
you must have desisted
they must have desisted	I must have been desisting
you must have been desisting
he must have been desisting
we must have been desisting
you must have been desisting
they must have been desisting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't desist
you mustn't desist
he mustn't desist
we mustn't desist
you mustn't desist
they mustn't desist 	I mustn't be desisting
you mustn't be desisting
he mustn't be desisting
we mustn't be desisting
you mustn't be desisting
they mustn't be desisting	I mustn't have desisted
you mustn't have desisted
he mustn't have desisted
we mustn't have desisted
you mustn't have desisted
they mustn't have desisted	I mustn't have been desisting
you mustn't have been desisting
he mustn't have been desisting
we mustn't have been desisting
you mustn't have been desisting
they mustn't have been desisting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I desist?
must you desist?
must he desist?
must we desist?
must you desist?
must they desist? 	must I be desisting?
must you be desisting?
must he be desisting?
must we be desisting?
must you be desisting?
must they be desisting? 	must I have desisted?
must you have desisted?
must he have desisted?
must we have desisted?
must you have desisted?
must they have desisted? 	must I have been desisting?
must you have been desisting?
must he have been desisting?
must we have been desisting?
must you have been desisting?
must they have been desisting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I desist?
mustn't you desist?
mustn't he desist?
mustn't we desist?
mustn't you desist?
mustn't they desist? 	mustn't I be desisting?
mustn't you be desisting?
mustn't he be desisting?
mustn't we be desisting?
mustn't you be desisting?
mustn't they be desisting? 	mustn't I have desisted?
mustn't you have desisted?
mustn't he have desisted?
mustn't we have desisted?
mustn't you have desisted?
mustn't they have desisted? 	mustn't I have been desisting?
mustn't you have been desisting?
mustn't he have been desisting?
mustn't we have been desisting?
mustn't you have been desisting?
mustn't they have been desisting?