could riff
Verbe régulier : riff - riffed- riffed

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I could riff
you could riff
she could riff
we could riff
you could riff
they could riff 	I could be riffing
you could be riffing
she could be riffing
we could be riffing
you could be riffing
they could be riffing	I could have riffed
you could have riffed
she 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
she could have been riffing
we could have been riffing
you could have been riffing
they could have been riffing	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I couldn't riff
you couldn't riff
she 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
she couldn't be riffing
we couldn't be riffing
you couldn't be riffing
they couldn't be riffing	I couldn't have riffed
you couldn't have riffed
she 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
she couldn't have been riffing
we couldn't have been riffing
you couldn't have been riffing
they couldn't have been riffing	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
could I riff?
could you riff?
could she riff?
could we riff?
could you riff?
could they riff? 	could I be riffing?
could you be riffing?
could she be riffing?
could we be riffing?
could you be riffing?
could they be riffing? 	could I have riffed?
could you have riffed?
could she 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 she have been riffing?
could we have been riffing?
could you have been riffing?
could they have been riffing? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
couldn't I riff?
couldn't you riff?
couldn't she 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 she be riffing?
couldn't we be riffing?
couldn't you be riffing?
couldn't they be riffing? 	couldn't I have riffed?
couldn't you have riffed?
couldn't she 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 she have been riffing?
couldn't we have been riffing?
couldn't you have been riffing?
couldn't they have been riffing?