could rolf
Regular verb: rolf - rolfed- rolfed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could rolf
you could rolf
he could rolf
we could rolf
you could rolf
they could rolf 	I could be rolfing
you could be rolfing
he could be rolfing
we could be rolfing
you could be rolfing
they could be rolfing	I could have rolfed
you could have rolfed
he could have rolfed
we could have rolfed
you could have rolfed
they could have rolfed	I could have been rolfing
you could have been rolfing
he could have been rolfing
we could have been rolfing
you could have been rolfing
they could have been rolfing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't rolf
you couldn't rolf
he couldn't rolf
we couldn't rolf
you couldn't rolf
they couldn't rolf 	I couldn't be rolfing
you couldn't be rolfing
he couldn't be rolfing
we couldn't be rolfing
you couldn't be rolfing
they couldn't be rolfing	I couldn't have rolfed
you couldn't have rolfed
he couldn't have rolfed
we couldn't have rolfed
you couldn't have rolfed
they couldn't have rolfed	I couldn't have been rolfing
you couldn't have been rolfing
he couldn't have been rolfing
we couldn't have been rolfing
you couldn't have been rolfing
they couldn't have been rolfing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I rolf?
could you rolf?
could he rolf?
could we rolf?
could you rolf?
could they rolf? 	could I be rolfing?
could you be rolfing?
could he be rolfing?
could we be rolfing?
could you be rolfing?
could they be rolfing? 	could I have rolfed?
could you have rolfed?
could he have rolfed?
could we have rolfed?
could you have rolfed?
could they have rolfed? 	could I have been rolfing?
could you have been rolfing?
could he have been rolfing?
could we have been rolfing?
could you have been rolfing?
could they have been rolfing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I rolf?
couldn't you rolf?
couldn't he rolf?
couldn't we rolf?
couldn't you rolf?
couldn't they rolf? 	couldn't I be rolfing?
couldn't you be rolfing?
couldn't he be rolfing?
couldn't we be rolfing?
couldn't you be rolfing?
couldn't they be rolfing? 	couldn't I have rolfed?
couldn't you have rolfed?
couldn't he have rolfed?
couldn't we have rolfed?
couldn't you have rolfed?
couldn't they have rolfed? 	couldn't I have been rolfing?
couldn't you have been rolfing?
couldn't he have been rolfing?
couldn't we have been rolfing?
couldn't you have been rolfing?
couldn't they have been rolfing?