must unjam
Regular verb: unjam - unjamed- unjamed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must unjam
you must unjam
he must unjam
we must unjam
you must unjam
they must unjam 	I must be unjaming
you must be unjaming
he must be unjaming
we must be unjaming
you must be unjaming
they must be unjaming	I must have unjamed
you must have unjamed
he must have unjamed
we must have unjamed
you must have unjamed
they must have unjamed	I must have been unjaming
you must have been unjaming
he must have been unjaming
we must have been unjaming
you must have been unjaming
they must have been unjaming	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't unjam
you mustn't unjam
he mustn't unjam
we mustn't unjam
you mustn't unjam
they mustn't unjam 	I mustn't be unjaming
you mustn't be unjaming
he mustn't be unjaming
we mustn't be unjaming
you mustn't be unjaming
they mustn't be unjaming	I mustn't have unjamed
you mustn't have unjamed
he mustn't have unjamed
we mustn't have unjamed
you mustn't have unjamed
they mustn't have unjamed	I mustn't have been unjaming
you mustn't have been unjaming
he mustn't have been unjaming
we mustn't have been unjaming
you mustn't have been unjaming
they mustn't have been unjaming	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I unjam?
must you unjam?
must he unjam?
must we unjam?
must you unjam?
must they unjam? 	must I be unjaming?
must you be unjaming?
must he be unjaming?
must we be unjaming?
must you be unjaming?
must they be unjaming? 	must I have unjamed?
must you have unjamed?
must he have unjamed?
must we have unjamed?
must you have unjamed?
must they have unjamed? 	must I have been unjaming?
must you have been unjaming?
must he have been unjaming?
must we have been unjaming?
must you have been unjaming?
must they have been unjaming? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I unjam?
mustn't you unjam?
mustn't he unjam?
mustn't we unjam?
mustn't you unjam?
mustn't they unjam? 	mustn't I be unjaming?
mustn't you be unjaming?
mustn't he be unjaming?
mustn't we be unjaming?
mustn't you be unjaming?
mustn't they be unjaming? 	mustn't I have unjamed?
mustn't you have unjamed?
mustn't he have unjamed?
mustn't we have unjamed?
mustn't you have unjamed?
mustn't they have unjamed? 	mustn't I have been unjaming?
mustn't you have been unjaming?
mustn't he have been unjaming?
mustn't we have been unjaming?
mustn't you have been unjaming?
mustn't they have been unjaming?