I could barnstorm you could barnstorm he could barnstorm we could barnstorm you could barnstorm they could barnstorm
V-ing form
I could be barnstorming you could be barnstorming he could be barnstorming we could be barnstorming you could be barnstorming they could be barnstorming
Perfect
I could have barnstormed you could have barnstormed he could have barnstormed we could have barnstormed you could have barnstormed they could have barnstormed
V-ing perfect
I could have been barnstorming you could have been barnstorming he could have been barnstorming we could have been barnstorming you could have been barnstorming they could have been barnstorming
Negation
Simple form
I couldn't barnstorm you couldn't barnstorm he couldn't barnstorm we couldn't barnstorm you couldn't barnstorm they couldn't barnstorm
V-ing form
I couldn't be barnstorming you couldn't be barnstorming he couldn't be barnstorming we couldn't be barnstorming you couldn't be barnstorming they couldn't be barnstorming
Perfect
I couldn't have barnstormed you couldn't have barnstormed he couldn't have barnstormed we couldn't have barnstormed you couldn't have barnstormed they couldn't have barnstormed
V-ing perfect
I couldn't have been barnstorming you couldn't have been barnstorming he couldn't have been barnstorming we couldn't have been barnstorming you couldn't have been barnstorming they couldn't have been barnstorming
Interrogative form
Simple form
could I barnstorm? could you barnstorm? could he barnstorm? could we barnstorm? could you barnstorm? could they barnstorm?
V-ing form
could I be barnstorming? could you be barnstorming? could he be barnstorming? could we be barnstorming? could you be barnstorming? could they be barnstorming?
Perfect
could I have barnstormed? could you have barnstormed? could he have barnstormed? could we have barnstormed? could you have barnstormed? could they have barnstormed?
V-ing perfect
could I have been barnstorming? could you have been barnstorming? could he have been barnstorming? could we have been barnstorming? could you have been barnstorming? could they have been barnstorming?
Interro-negative form
Simple form
couldn't I barnstorm? couldn't you barnstorm? couldn't he barnstorm? couldn't we barnstorm? couldn't you barnstorm? couldn't they barnstorm?
V-ing form
couldn't I be barnstorming? couldn't you be barnstorming? couldn't he be barnstorming? couldn't we be barnstorming? couldn't you be barnstorming? couldn't they be barnstorming?
Perfect
couldn't I have barnstormed? couldn't you have barnstormed? couldn't he have barnstormed? couldn't we have barnstormed? couldn't you have barnstormed? couldn't they have barnstormed?
V-ing perfect
couldn't I have been barnstorming? couldn't you have been barnstorming? couldn't he have been barnstorming? couldn't we have been barnstorming? couldn't you have been barnstorming? couldn't they have been barnstorming?