must understate
Regular verb: understate - understated- understated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must understate
you must understate
she must understate
we must understate
you must understate
they must understate 	I must be understating
you must be understating
she must be understating
we must be understating
you must be understating
they must be understating	I must have understated
you must have understated
she must have understated
we must have understated
you must have understated
they must have understated	I must have been understating
you must have been understating
she must have been understating
we must have been understating
you must have been understating
they must have been understating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't understate
you mustn't understate
she mustn't understate
we mustn't understate
you mustn't understate
they mustn't understate 	I mustn't be understating
you mustn't be understating
she mustn't be understating
we mustn't be understating
you mustn't be understating
they mustn't be understating	I mustn't have understated
you mustn't have understated
she mustn't have understated
we mustn't have understated
you mustn't have understated
they mustn't have understated	I mustn't have been understating
you mustn't have been understating
she mustn't have been understating
we mustn't have been understating
you mustn't have been understating
they mustn't have been understating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I understate?
must you understate?
must she understate?
must we understate?
must you understate?
must they understate? 	must I be understating?
must you be understating?
must she be understating?
must we be understating?
must you be understating?
must they be understating? 	must I have understated?
must you have understated?
must she have understated?
must we have understated?
must you have understated?
must they have understated? 	must I have been understating?
must you have been understating?
must she have been understating?
must we have been understating?
must you have been understating?
must they have been understating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I understate?
mustn't you understate?
mustn't she understate?
mustn't we understate?
mustn't you understate?
mustn't they understate? 	mustn't I be understating?
mustn't you be understating?
mustn't she be understating?
mustn't we be understating?
mustn't you be understating?
mustn't they be understating? 	mustn't I have understated?
mustn't you have understated?
mustn't she have understated?
mustn't we have understated?
mustn't you have understated?
mustn't they have understated? 	mustn't I have been understating?
mustn't you have been understating?
mustn't she have been understating?
mustn't we have been understating?
mustn't you have been understating?
mustn't they have been understating?