could warn
Verbo regular: warn - warned- warned

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could warn
you could warn
he could warn
we could warn
you could warn
they could warn 	I could be warning
you could be warning
he could be warning
we could be warning
you could be warning
they could be warning	I could have warned
you could have warned
he could have warned
we could have warned
you could have warned
they could have warned	I could have been warning
you could have been warning
he could have been warning
we could have been warning
you could have been warning
they could have been warning	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not warn
you could not warn
he could not warn
we could not warn
you could not warn
they could not warn 	I could not be warning
you could not be warning
he could not be warning
we could not be warning
you could not be warning
they could not be warning	I could not have warned
you could not have warned
he could not have warned
we could not have warned
you could not have warned
they could not have warned	I could not have been warning
you could not have been warning
he could not have been warning
we could not have been warning
you could not have been warning
they could not have been warning	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I warn?
could you warn?
could he warn?
could we warn?
could you warn?
could they warn? 	could I be warning?
could you be warning?
could he be warning?
could we be warning?
could you be warning?
could they be warning? 	could I have warned?
could you have warned?
could he have warned?
could we have warned?
could you have warned?
could they have warned? 	could I have been warning?
could you have been warning?
could he have been warning?
could we have been warning?
could you have been warning?
could they have been warning? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not warn?
could you not warn?
could he not warn?
could we not warn?
could you not warn?
could they not warn? 	could I not be warning?
could you not be warning?
could he not be warning?
could we not be warning?
could you not be warning?
could they not be warning? 	could I not have warned?
could you not have warned?
could he not have warned?
could we not have warned?
could you not have warned?
could they not have warned? 	could I not have been warning?
could you not have been warning?
could he not have been warning?
could we not have been warning?
could you not have been warning?
could they not have been warning?