could tune
Verbo regular: tune - tuned- tuned

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could tune
you could tune
he could tune
we could tune
you could tune
they could tune 	I could be tuning
you could be tuning
he could be tuning
we could be tuning
you could be tuning
they could be tuning	I could have tuned
you could have tuned
he could have tuned
we could have tuned
you could have tuned
they could have tuned	I could have been tuning
you could have been tuning
he could have been tuning
we could have been tuning
you could have been tuning
they could have been tuning	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't tune
you couldn't tune
he couldn't tune
we couldn't tune
you couldn't tune
they couldn't tune 	I couldn't be tuning
you couldn't be tuning
he couldn't be tuning
we couldn't be tuning
you couldn't be tuning
they couldn't be tuning	I couldn't have tuned
you couldn't have tuned
he couldn't have tuned
we couldn't have tuned
you couldn't have tuned
they couldn't have tuned	I couldn't have been tuning
you couldn't have been tuning
he couldn't have been tuning
we couldn't have been tuning
you couldn't have been tuning
they couldn't have been tuning	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I tune?
could you tune?
could he tune?
could we tune?
could you tune?
could they tune? 	could I be tuning?
could you be tuning?
could he be tuning?
could we be tuning?
could you be tuning?
could they be tuning? 	could I have tuned?
could you have tuned?
could he have tuned?
could we have tuned?
could you have tuned?
could they have tuned? 	could I have been tuning?
could you have been tuning?
could he have been tuning?
could we have been tuning?
could you have been tuning?
could they have been tuning? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I tune?
couldn't you tune?
couldn't he tune?
couldn't we tune?
couldn't you tune?
couldn't they tune? 	couldn't I be tuning?
couldn't you be tuning?
couldn't he be tuning?
couldn't we be tuning?
couldn't you be tuning?
couldn't they be tuning? 	couldn't I have tuned?
couldn't you have tuned?
couldn't he have tuned?
couldn't we have tuned?
couldn't you have tuned?
couldn't they have tuned? 	couldn't I have been tuning?
couldn't you have been tuning?
couldn't he have been tuning?
couldn't we have been tuning?
couldn't you have been tuning?
couldn't they have been tuning?