must rub
Verbo regular: rub - rubbed- rubbed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must rub
you must rub
he must rub
we must rub
you must rub
they must rub 	I must be rubbing
you must be rubbing
he must be rubbing
we must be rubbing
you must be rubbing
they must be rubbing	I must have rubbed
you must have rubbed
he must have rubbed
we must have rubbed
you must have rubbed
they must have rubbed	I must have been rubbing
you must have been rubbing
he must have been rubbing
we must have been rubbing
you must have been rubbing
they must have been rubbing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't rub
you mustn't rub
he mustn't rub
we mustn't rub
you mustn't rub
they mustn't rub 	I mustn't be rubbing
you mustn't be rubbing
he mustn't be rubbing
we mustn't be rubbing
you mustn't be rubbing
they mustn't be rubbing	I mustn't have rubbed
you mustn't have rubbed
he mustn't have rubbed
we mustn't have rubbed
you mustn't have rubbed
they mustn't have rubbed	I mustn't have been rubbing
you mustn't have been rubbing
he mustn't have been rubbing
we mustn't have been rubbing
you mustn't have been rubbing
they mustn't have been rubbing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I rub?
must you rub?
must he rub?
must we rub?
must you rub?
must they rub? 	must I be rubbing?
must you be rubbing?
must he be rubbing?
must we be rubbing?
must you be rubbing?
must they be rubbing? 	must I have rubbed?
must you have rubbed?
must he have rubbed?
must we have rubbed?
must you have rubbed?
must they have rubbed? 	must I have been rubbing?
must you have been rubbing?
must he have been rubbing?
must we have been rubbing?
must you have been rubbing?
must they have been rubbing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I rub?
mustn't you rub?
mustn't he rub?
mustn't we rub?
mustn't you rub?
mustn't they rub? 	mustn't I be rubbing?
mustn't you be rubbing?
mustn't he be rubbing?
mustn't we be rubbing?
mustn't you be rubbing?
mustn't they be rubbing? 	mustn't I have rubbed?
mustn't you have rubbed?
mustn't he have rubbed?
mustn't we have rubbed?
mustn't you have rubbed?
mustn't they have rubbed? 	mustn't I have been rubbing?
mustn't you have been rubbing?
mustn't he have been rubbing?
mustn't we have been rubbing?
mustn't you have been rubbing?
mustn't they have been rubbing?