could rub
Verbo regular: rub - rubbed- rubbed

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

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

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

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