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 couldn't riff you couldn't riff he couldn't riff we couldn't riff you couldn't riff they couldn't riff	I couldn't be riffing you couldn't be riffing he couldn't be riffing we couldn't be riffing you couldn't be riffing they couldn't be riffing
Perfecto	Perfecto con V-ing
I couldn't have riffed you couldn't have riffed he couldn't have riffed we couldn't have riffed you couldn't have riffed they couldn't have riffed	I couldn't have been riffing you couldn't have been riffing he couldn't have been riffing we couldn't have been riffing you couldn't have been riffing they couldn't 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
couldn't I riff? couldn't you riff? couldn't he riff? couldn't we riff? couldn't you riff? couldn't they riff?	couldn't I be riffing? couldn't you be riffing? couldn't he be riffing? couldn't we be riffing? couldn't you be riffing? couldn't they be riffing?
Perfecto	Perfecto con V-ing
couldn't I have riffed? couldn't you have riffed? couldn't he have riffed? couldn't we have riffed? couldn't you have riffed? couldn't they have riffed?	couldn't I have been riffing? couldn't you have been riffing? couldn't he have been riffing? couldn't we have been riffing? couldn't you have been riffing? couldn't they have been riffing?