could yo-yo
Verbo regular: yo-yo - yo-yoed- yo-yoed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could yo-yo
you could yo-yo
he could yo-yo
we could yo-yo
you could yo-yo
they could yo-yo 	I could be yo-yoing
you could be yo-yoing
he could be yo-yoing
we could be yo-yoing
you could be yo-yoing
they could be yo-yoing	I could have yo-yoed
you could have yo-yoed
he could have yo-yoed
we could have yo-yoed
you could have yo-yoed
they could have yo-yoed	I could have been yo-yoing
you could have been yo-yoing
he could have been yo-yoing
we could have been yo-yoing
you could have been yo-yoing
they could have been yo-yoing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't yo-yo
you couldn't yo-yo
he couldn't yo-yo
we couldn't yo-yo
you couldn't yo-yo
they couldn't yo-yo 	I couldn't be yo-yoing
you couldn't be yo-yoing
he couldn't be yo-yoing
we couldn't be yo-yoing
you couldn't be yo-yoing
they couldn't be yo-yoing	I couldn't have yo-yoed
you couldn't have yo-yoed
he couldn't have yo-yoed
we couldn't have yo-yoed
you couldn't have yo-yoed
they couldn't have yo-yoed	I couldn't have been yo-yoing
you couldn't have been yo-yoing
he couldn't have been yo-yoing
we couldn't have been yo-yoing
you couldn't have been yo-yoing
they couldn't have been yo-yoing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I yo-yo?
could you yo-yo?
could he yo-yo?
could we yo-yo?
could you yo-yo?
could they yo-yo? 	could I be yo-yoing?
could you be yo-yoing?
could he be yo-yoing?
could we be yo-yoing?
could you be yo-yoing?
could they be yo-yoing? 	could I have yo-yoed?
could you have yo-yoed?
could he have yo-yoed?
could we have yo-yoed?
could you have yo-yoed?
could they have yo-yoed? 	could I have been yo-yoing?
could you have been yo-yoing?
could he have been yo-yoing?
could we have been yo-yoing?
could you have been yo-yoing?
could they have been yo-yoing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I yo-yo?
couldn't you yo-yo?
couldn't he yo-yo?
couldn't we yo-yo?
couldn't you yo-yo?
couldn't they yo-yo? 	couldn't I be yo-yoing?
couldn't you be yo-yoing?
couldn't he be yo-yoing?
couldn't we be yo-yoing?
couldn't you be yo-yoing?
couldn't they be yo-yoing? 	couldn't I have yo-yoed?
couldn't you have yo-yoed?
couldn't he have yo-yoed?
couldn't we have yo-yoed?
couldn't you have yo-yoed?
couldn't they have yo-yoed? 	couldn't I have been yo-yoing?
couldn't you have been yo-yoing?
couldn't he have been yo-yoing?
couldn't we have been yo-yoing?
couldn't you have been yo-yoing?
couldn't they have been yo-yoing?