must encumber
Regular verb: encumber - encumbered- encumbered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must encumber
you must encumber
he must encumber
we must encumber
you must encumber
they must encumber 	I must be encumbering
you must be encumbering
he must be encumbering
we must be encumbering
you must be encumbering
they must be encumbering	I must have encumbered
you must have encumbered
he must have encumbered
we must have encumbered
you must have encumbered
they must have encumbered	I must have been encumbering
you must have been encumbering
he must have been encumbering
we must have been encumbering
you must have been encumbering
they must have been encumbering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't encumber
you mustn't encumber
he mustn't encumber
we mustn't encumber
you mustn't encumber
they mustn't encumber 	I mustn't be encumbering
you mustn't be encumbering
he mustn't be encumbering
we mustn't be encumbering
you mustn't be encumbering
they mustn't be encumbering	I mustn't have encumbered
you mustn't have encumbered
he mustn't have encumbered
we mustn't have encumbered
you mustn't have encumbered
they mustn't have encumbered	I mustn't have been encumbering
you mustn't have been encumbering
he mustn't have been encumbering
we mustn't have been encumbering
you mustn't have been encumbering
they mustn't have been encumbering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I encumber?
must you encumber?
must he encumber?
must we encumber?
must you encumber?
must they encumber? 	must I be encumbering?
must you be encumbering?
must he be encumbering?
must we be encumbering?
must you be encumbering?
must they be encumbering? 	must I have encumbered?
must you have encumbered?
must he have encumbered?
must we have encumbered?
must you have encumbered?
must they have encumbered? 	must I have been encumbering?
must you have been encumbering?
must he have been encumbering?
must we have been encumbering?
must you have been encumbering?
must they have been encumbering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I encumber?
mustn't you encumber?
mustn't he encumber?
mustn't we encumber?
mustn't you encumber?
mustn't they encumber? 	mustn't I be encumbering?
mustn't you be encumbering?
mustn't he be encumbering?
mustn't we be encumbering?
mustn't you be encumbering?
mustn't they be encumbering? 	mustn't I have encumbered?
mustn't you have encumbered?
mustn't he have encumbered?
mustn't we have encumbered?
mustn't you have encumbered?
mustn't they have encumbered? 	mustn't I have been encumbering?
mustn't you have been encumbering?
mustn't he have been encumbering?
mustn't we have been encumbering?
mustn't you have been encumbering?
mustn't they have been encumbering?