must devalue
Regular verb: devalue - devalued- devalued

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must devalue
you must devalue
she must devalue
we must devalue
you must devalue
they must devalue 	I must be devaluing
you must be devaluing
she must be devaluing
we must be devaluing
you must be devaluing
they must be devaluing	I must have devalued
you must have devalued
she must have devalued
we must have devalued
you must have devalued
they must have devalued	I must have been devaluing
you must have been devaluing
she must have been devaluing
we must have been devaluing
you must have been devaluing
they must have been devaluing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't devalue
you mustn't devalue
she mustn't devalue
we mustn't devalue
you mustn't devalue
they mustn't devalue 	I mustn't be devaluing
you mustn't be devaluing
she mustn't be devaluing
we mustn't be devaluing
you mustn't be devaluing
they mustn't be devaluing	I mustn't have devalued
you mustn't have devalued
she mustn't have devalued
we mustn't have devalued
you mustn't have devalued
they mustn't have devalued	I mustn't have been devaluing
you mustn't have been devaluing
she mustn't have been devaluing
we mustn't have been devaluing
you mustn't have been devaluing
they mustn't have been devaluing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I devalue?
must you devalue?
must she devalue?
must we devalue?
must you devalue?
must they devalue? 	must I be devaluing?
must you be devaluing?
must she be devaluing?
must we be devaluing?
must you be devaluing?
must they be devaluing? 	must I have devalued?
must you have devalued?
must she have devalued?
must we have devalued?
must you have devalued?
must they have devalued? 	must I have been devaluing?
must you have been devaluing?
must she have been devaluing?
must we have been devaluing?
must you have been devaluing?
must they have been devaluing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I devalue?
mustn't you devalue?
mustn't she devalue?
mustn't we devalue?
mustn't you devalue?
mustn't they devalue? 	mustn't I be devaluing?
mustn't you be devaluing?
mustn't she be devaluing?
mustn't we be devaluing?
mustn't you be devaluing?
mustn't they be devaluing? 	mustn't I have devalued?
mustn't you have devalued?
mustn't she have devalued?
mustn't we have devalued?
mustn't you have devalued?
mustn't they have devalued? 	mustn't I have been devaluing?
mustn't you have been devaluing?
mustn't she have been devaluing?
mustn't we have been devaluing?
mustn't you have been devaluing?
mustn't they have been devaluing?