could smooth
Verbo regular: smooth - smoothed- smoothed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could smooth
you could smooth
she could smooth
we could smooth
you could smooth
they could smooth 	I could be smoothing
you could be smoothing
she could be smoothing
we could be smoothing
you could be smoothing
they could be smoothing	I could have smoothed
you could have smoothed
she could have smoothed
we could have smoothed
you could have smoothed
they could have smoothed	I could have been smoothing
you could have been smoothing
she could have been smoothing
we could have been smoothing
you could have been smoothing
they could have been smoothing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not smooth
you could not smooth
she could not smooth
we could not smooth
you could not smooth
they could not smooth 	I could not be smoothing
you could not be smoothing
she could not be smoothing
we could not be smoothing
you could not be smoothing
they could not be smoothing	I could not have smoothed
you could not have smoothed
she could not have smoothed
we could not have smoothed
you could not have smoothed
they could not have smoothed	I could not have been smoothing
you could not have been smoothing
she could not have been smoothing
we could not have been smoothing
you could not have been smoothing
they could not have been smoothing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I smooth?
could you smooth?
could she smooth?
could we smooth?
could you smooth?
could they smooth? 	could I be smoothing?
could you be smoothing?
could she be smoothing?
could we be smoothing?
could you be smoothing?
could they be smoothing? 	could I have smoothed?
could you have smoothed?
could she have smoothed?
could we have smoothed?
could you have smoothed?
could they have smoothed? 	could I have been smoothing?
could you have been smoothing?
could she have been smoothing?
could we have been smoothing?
could you have been smoothing?
could they have been smoothing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not smooth?
could you not smooth?
could she not smooth?
could we not smooth?
could you not smooth?
could they not smooth? 	could I not be smoothing?
could you not be smoothing?
could she not be smoothing?
could we not be smoothing?
could you not be smoothing?
could they not be smoothing? 	could I not have smoothed?
could you not have smoothed?
could she not have smoothed?
could we not have smoothed?
could you not have smoothed?
could they not have smoothed? 	could I not have been smoothing?
could you not have been smoothing?
could she not have been smoothing?
could we not have been smoothing?
could you not have been smoothing?
could they not have been smoothing?