English verb conjugation
COULD ROLF

Regular verb: rolf - rolfed - rolfed

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
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
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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?