English verb conjugation
COULD COUNTERVAIL

Regular verb: countervail - countervailed - countervailed

Affirmation

Simple form	V-ing form
I could countervail you could countervail he could countervail we could countervail you could countervail they could countervail	I could be countervailing you could be countervailing he could be countervailing we could be countervailing you could be countervailing they could be countervailing
Perfect	V-ing perfect
I could have countervailed you could have countervailed he could have countervailed we could have countervailed you could have countervailed they could have countervailed	I could have been countervailing you could have been countervailing he could have been countervailing we could have been countervailing you could have been countervailing they could have been countervailing

Negation

Simple form	V-ing form
I couldn't countervail you couldn't countervail he couldn't countervail we couldn't countervail you couldn't countervail they couldn't countervail	I couldn't be countervailing you couldn't be countervailing he couldn't be countervailing we couldn't be countervailing you couldn't be countervailing they couldn't be countervailing
Perfect	V-ing perfect
I couldn't have countervailed you couldn't have countervailed he couldn't have countervailed we couldn't have countervailed you couldn't have countervailed they couldn't have countervailed	I couldn't have been countervailing you couldn't have been countervailing he couldn't have been countervailing we couldn't have been countervailing you couldn't have been countervailing they couldn't have been countervailing

Interrogative form

Simple form	V-ing form
could I countervail? could you countervail? could he countervail? could we countervail? could you countervail? could they countervail?	could I be countervailing? could you be countervailing? could he be countervailing? could we be countervailing? could you be countervailing? could they be countervailing?
Perfect	V-ing perfect
could I have countervailed? could you have countervailed? could he have countervailed? could we have countervailed? could you have countervailed? could they have countervailed?	could I have been countervailing? could you have been countervailing? could he have been countervailing? could we have been countervailing? could you have been countervailing? could they have been countervailing?

Interro-negative form

Simple form	V-ing form
couldn't I countervail? couldn't you countervail? couldn't he countervail? couldn't we countervail? couldn't you countervail? couldn't they countervail?	couldn't I be countervailing? couldn't you be countervailing? couldn't he be countervailing? couldn't we be countervailing? couldn't you be countervailing? couldn't they be countervailing?
Perfect	V-ing perfect
couldn't I have countervailed? couldn't you have countervailed? couldn't he have countervailed? couldn't we have countervailed? couldn't you have countervailed? couldn't they have countervailed?	couldn't I have been countervailing? couldn't you have been countervailing? couldn't he have been countervailing? couldn't we have been countervailing? couldn't you have been countervailing? couldn't they have been countervailing?