English verb conjugation
CAN COUNTERVAIL

Regular verb: countervail - countervailed - countervailed

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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