could riffle
Regular verb: riffle - riffled- riffled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could riffle
you could riffle
he could riffle
we could riffle
you could riffle
they could riffle 	I could be riffling
you could be riffling
he could be riffling
we could be riffling
you could be riffling
they could be riffling	I could have riffled
you could have riffled
he could have riffled
we could have riffled
you could have riffled
they could have riffled	I could have been riffling
you could have been riffling
he could have been riffling
we could have been riffling
you could have been riffling
they could have been riffling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't riffle
you couldn't riffle
he couldn't riffle
we couldn't riffle
you couldn't riffle
they couldn't riffle 	I couldn't be riffling
you couldn't be riffling
he couldn't be riffling
we couldn't be riffling
you couldn't be riffling
they couldn't be riffling	I couldn't have riffled
you couldn't have riffled
he couldn't have riffled
we couldn't have riffled
you couldn't have riffled
they couldn't have riffled	I couldn't have been riffling
you couldn't have been riffling
he couldn't have been riffling
we couldn't have been riffling
you couldn't have been riffling
they couldn't have been riffling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I riffle?
could you riffle?
could he riffle?
could we riffle?
could you riffle?
could they riffle? 	could I be riffling?
could you be riffling?
could he be riffling?
could we be riffling?
could you be riffling?
could they be riffling? 	could I have riffled?
could you have riffled?
could he have riffled?
could we have riffled?
could you have riffled?
could they have riffled? 	could I have been riffling?
could you have been riffling?
could he have been riffling?
could we have been riffling?
could you have been riffling?
could they have been riffling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I riffle?
couldn't you riffle?
couldn't he riffle?
couldn't we riffle?
couldn't you riffle?
couldn't they riffle? 	couldn't I be riffling?
couldn't you be riffling?
couldn't he be riffling?
couldn't we be riffling?
couldn't you be riffling?
couldn't they be riffling? 	couldn't I have riffled?
couldn't you have riffled?
couldn't he have riffled?
couldn't we have riffled?
couldn't you have riffled?
couldn't they have riffled? 	couldn't I have been riffling?
couldn't you have been riffling?
couldn't he have been riffling?
couldn't we have been riffling?
couldn't you have been riffling?
couldn't they have been riffling?