must desert
Regular verb: desert - deserted- deserted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must desert
you must desert
he must desert
we must desert
you must desert
they must desert 	I must be deserting
you must be deserting
he must be deserting
we must be deserting
you must be deserting
they must be deserting	I must have deserted
you must have deserted
he must have deserted
we must have deserted
you must have deserted
they must have deserted	I must have been deserting
you must have been deserting
he must have been deserting
we must have been deserting
you must have been deserting
they must have been deserting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't desert
you mustn't desert
he mustn't desert
we mustn't desert
you mustn't desert
they mustn't desert 	I mustn't be deserting
you mustn't be deserting
he mustn't be deserting
we mustn't be deserting
you mustn't be deserting
they mustn't be deserting	I mustn't have deserted
you mustn't have deserted
he mustn't have deserted
we mustn't have deserted
you mustn't have deserted
they mustn't have deserted	I mustn't have been deserting
you mustn't have been deserting
he mustn't have been deserting
we mustn't have been deserting
you mustn't have been deserting
they mustn't have been deserting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I desert?
must you desert?
must he desert?
must we desert?
must you desert?
must they desert? 	must I be deserting?
must you be deserting?
must he be deserting?
must we be deserting?
must you be deserting?
must they be deserting? 	must I have deserted?
must you have deserted?
must he have deserted?
must we have deserted?
must you have deserted?
must they have deserted? 	must I have been deserting?
must you have been deserting?
must he have been deserting?
must we have been deserting?
must you have been deserting?
must they have been deserting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I desert?
mustn't you desert?
mustn't he desert?
mustn't we desert?
mustn't you desert?
mustn't they desert? 	mustn't I be deserting?
mustn't you be deserting?
mustn't he be deserting?
mustn't we be deserting?
mustn't you be deserting?
mustn't they be deserting? 	mustn't I have deserted?
mustn't you have deserted?
mustn't he have deserted?
mustn't we have deserted?
mustn't you have deserted?
mustn't they have deserted? 	mustn't I have been deserting?
mustn't you have been deserting?
mustn't he have been deserting?
mustn't we have been deserting?
mustn't you have been deserting?
mustn't they have been deserting?