Conjugación del verbo inglés
COULD RIFF

Verbo regular: riff - riffed - riffed

Afirmación

Forma simple	Forma con V-ing
I could riff you could riff he could riff we could riff you could riff they could riff	I could be riffing you could be riffing he could be riffing we could be riffing you could be riffing they could be riffing
Perfecto	Perfecto con V-ing
I could have riffed you could have riffed he could have riffed we could have riffed you could have riffed they could have riffed	I could have been riffing you could have been riffing he could have been riffing we could have been riffing you could have been riffing they could have been riffing

Negación

Forma simple	Forma con V-ing
I could not riff you could not riff he could not riff we could not riff you could not riff they could not riff	I could not be riffing you could not be riffing he could not be riffing we could not be riffing you could not be riffing they could not be riffing
Perfecto	Perfecto con V-ing
I could not have riffed you could not have riffed he could not have riffed we could not have riffed you could not have riffed they could not have riffed	I could not have been riffing you could not have been riffing he could not have been riffing we could not have been riffing you could not have been riffing they could not have been riffing

Forma interrogativa

Forma simple	Forma con V-ing
could I riff? could you riff? could he riff? could we riff? could you riff? could they riff?	could I be riffing? could you be riffing? could he be riffing? could we be riffing? could you be riffing? could they be riffing?
Perfecto	Perfecto con V-ing
could I have riffed? could you have riffed? could he have riffed? could we have riffed? could you have riffed? could they have riffed?	could I have been riffing? could you have been riffing? could he have been riffing? could we have been riffing? could you have been riffing? could they have been riffing?

Forma interro-negativa

Forma simple	Forma con V-ing
could I not riff? could you not riff? could he not riff? could we not riff? could you not riff? could they not riff?	could I not be riffing? could you not be riffing? could he not be riffing? could we not be riffing? could you not be riffing? could they not be riffing?
Perfecto	Perfecto con V-ing
could I not have riffed? could you not have riffed? could he not have riffed? could we not have riffed? could you not have riffed? could they not have riffed?	could I not have been riffing? could you not have been riffing? could he not have been riffing? could we not have been riffing? could you not have been riffing? could they not have been riffing?