could heighten
Verbo regular: heighten - heightened- heightened

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could heighten
you could heighten
he could heighten
we could heighten
you could heighten
they could heighten 	I could be heightening
you could be heightening
he could be heightening
we could be heightening
you could be heightening
they could be heightening	I could have heightened
you could have heightened
he could have heightened
we could have heightened
you could have heightened
they could have heightened	I could have been heightening
you could have been heightening
he could have been heightening
we could have been heightening
you could have been heightening
they could have been heightening	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not heighten
you could not heighten
he could not heighten
we could not heighten
you could not heighten
they could not heighten 	I could not be heightening
you could not be heightening
he could not be heightening
we could not be heightening
you could not be heightening
they could not be heightening	I could not have heightened
you could not have heightened
he could not have heightened
we could not have heightened
you could not have heightened
they could not have heightened	I could not have been heightening
you could not have been heightening
he could not have been heightening
we could not have been heightening
you could not have been heightening
they could not have been heightening	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I heighten?
could you heighten?
could he heighten?
could we heighten?
could you heighten?
could they heighten? 	could I be heightening?
could you be heightening?
could he be heightening?
could we be heightening?
could you be heightening?
could they be heightening? 	could I have heightened?
could you have heightened?
could he have heightened?
could we have heightened?
could you have heightened?
could they have heightened? 	could I have been heightening?
could you have been heightening?
could he have been heightening?
could we have been heightening?
could you have been heightening?
could they have been heightening? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not heighten?
could you not heighten?
could he not heighten?
could we not heighten?
could you not heighten?
could they not heighten? 	could I not be heightening?
could you not be heightening?
could he not be heightening?
could we not be heightening?
could you not be heightening?
could they not be heightening? 	could I not have heightened?
could you not have heightened?
could he not have heightened?
could we not have heightened?
could you not have heightened?
could they not have heightened? 	could I not have been heightening?
could you not have been heightening?
could he not have been heightening?
could we not have been heightening?
could you not have been heightening?
could they not have been heightening?