must frown
Verbo regular: frown - frowned- frowned

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must frown
you must frown
he must frown
we must frown
you must frown
they must frown 	I must be frowning
you must be frowning
he must be frowning
we must be frowning
you must be frowning
they must be frowning	I must have frowned
you must have frowned
he must have frowned
we must have frowned
you must have frowned
they must have frowned	I must have been frowning
you must have been frowning
he must have been frowning
we must have been frowning
you must have been frowning
they must have been frowning	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't frown
you mustn't frown
he mustn't frown
we mustn't frown
you mustn't frown
they mustn't frown 	I mustn't be frowning
you mustn't be frowning
he mustn't be frowning
we mustn't be frowning
you mustn't be frowning
they mustn't be frowning	I mustn't have frowned
you mustn't have frowned
he mustn't have frowned
we mustn't have frowned
you mustn't have frowned
they mustn't have frowned	I mustn't have been frowning
you mustn't have been frowning
he mustn't have been frowning
we mustn't have been frowning
you mustn't have been frowning
they mustn't have been frowning	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I frown?
must you frown?
must he frown?
must we frown?
must you frown?
must they frown? 	must I be frowning?
must you be frowning?
must he be frowning?
must we be frowning?
must you be frowning?
must they be frowning? 	must I have frowned?
must you have frowned?
must he have frowned?
must we have frowned?
must you have frowned?
must they have frowned? 	must I have been frowning?
must you have been frowning?
must he have been frowning?
must we have been frowning?
must you have been frowning?
must they have been frowning? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I frown?
mustn't you frown?
mustn't he frown?
mustn't we frown?
mustn't you frown?
mustn't they frown? 	mustn't I be frowning?
mustn't you be frowning?
mustn't he be frowning?
mustn't we be frowning?
mustn't you be frowning?
mustn't they be frowning? 	mustn't I have frowned?
mustn't you have frowned?
mustn't he have frowned?
mustn't we have frowned?
mustn't you have frowned?
mustn't they have frowned? 	mustn't I have been frowning?
mustn't you have been frowning?
mustn't he have been frowning?
mustn't we have been frowning?
mustn't you have been frowning?
mustn't they have been frowning?