could discover
Verbo regular: discover - discovered- discovered

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could discover
you could discover
he could discover
we could discover
you could discover
they could discover 	I could be discovering
you could be discovering
he could be discovering
we could be discovering
you could be discovering
they could be discovering	I could have discovered
you could have discovered
he could have discovered
we could have discovered
you could have discovered
they could have discovered	I could have been discovering
you could have been discovering
he could have been discovering
we could have been discovering
you could have been discovering
they could have been discovering	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't discover
you couldn't discover
he couldn't discover
we couldn't discover
you couldn't discover
they couldn't discover 	I couldn't be discovering
you couldn't be discovering
he couldn't be discovering
we couldn't be discovering
you couldn't be discovering
they couldn't be discovering	I couldn't have discovered
you couldn't have discovered
he couldn't have discovered
we couldn't have discovered
you couldn't have discovered
they couldn't have discovered	I couldn't have been discovering
you couldn't have been discovering
he couldn't have been discovering
we couldn't have been discovering
you couldn't have been discovering
they couldn't have been discovering	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I discover?
could you discover?
could he discover?
could we discover?
could you discover?
could they discover? 	could I be discovering?
could you be discovering?
could he be discovering?
could we be discovering?
could you be discovering?
could they be discovering? 	could I have discovered?
could you have discovered?
could he have discovered?
could we have discovered?
could you have discovered?
could they have discovered? 	could I have been discovering?
could you have been discovering?
could he have been discovering?
could we have been discovering?
could you have been discovering?
could they have been discovering? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I discover?
couldn't you discover?
couldn't he discover?
couldn't we discover?
couldn't you discover?
couldn't they discover? 	couldn't I be discovering?
couldn't you be discovering?
couldn't he be discovering?
couldn't we be discovering?
couldn't you be discovering?
couldn't they be discovering? 	couldn't I have discovered?
couldn't you have discovered?
couldn't he have discovered?
couldn't we have discovered?
couldn't you have discovered?
couldn't they have discovered? 	couldn't I have been discovering?
couldn't you have been discovering?
couldn't he have been discovering?
couldn't we have been discovering?
couldn't you have been discovering?
couldn't they have been discovering?