must stem
Verbo regular: stem - stemmed- stemmed

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must stem
you must stem
he must stem
we must stem
you must stem
they must stem 	I must be stemming
you must be stemming
he must be stemming
we must be stemming
you must be stemming
they must be stemming	I must have stemmed
you must have stemmed
he must have stemmed
we must have stemmed
you must have stemmed
they must have stemmed	I must have been stemming
you must have been stemming
he must have been stemming
we must have been stemming
you must have been stemming
they must have been stemming	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't stem
you mustn't stem
he mustn't stem
we mustn't stem
you mustn't stem
they mustn't stem 	I mustn't be stemming
you mustn't be stemming
he mustn't be stemming
we mustn't be stemming
you mustn't be stemming
they mustn't be stemming	I mustn't have stemmed
you mustn't have stemmed
he mustn't have stemmed
we mustn't have stemmed
you mustn't have stemmed
they mustn't have stemmed	I mustn't have been stemming
you mustn't have been stemming
he mustn't have been stemming
we mustn't have been stemming
you mustn't have been stemming
they mustn't have been stemming	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I stem?
must you stem?
must he stem?
must we stem?
must you stem?
must they stem? 	must I be stemming?
must you be stemming?
must he be stemming?
must we be stemming?
must you be stemming?
must they be stemming? 	must I have stemmed?
must you have stemmed?
must he have stemmed?
must we have stemmed?
must you have stemmed?
must they have stemmed? 	must I have been stemming?
must you have been stemming?
must he have been stemming?
must we have been stemming?
must you have been stemming?
must they have been stemming? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I stem?
mustn't you stem?
mustn't he stem?
mustn't we stem?
mustn't you stem?
mustn't they stem? 	mustn't I be stemming?
mustn't you be stemming?
mustn't he be stemming?
mustn't we be stemming?
mustn't you be stemming?
mustn't they be stemming? 	mustn't I have stemmed?
mustn't you have stemmed?
mustn't he have stemmed?
mustn't we have stemmed?
mustn't you have stemmed?
mustn't they have stemmed? 	mustn't I have been stemming?
mustn't you have been stemming?
mustn't he have been stemming?
mustn't we have been stemming?
mustn't you have been stemming?
mustn't they have been stemming?