English verb conjugation
CAN VAIL

Regular verb: vail - vailed - vailed

Affirmation

Simple form	V-ing form
I can vail you can vail he can vail we can vail you can vail they can vail	I can be vailing you can be vailing he can be vailing we can be vailing you can be vailing they can be vailing
Perfect	V-ing perfect
I can have vailed you can have vailed he can have vailed we can have vailed you can have vailed they can have vailed	I can have been vailing you can have been vailing he can have been vailing we can have been vailing you can have been vailing they can have been vailing

Negation

Simple form	V-ing form
I can't vail you can't vail he can't vail we can't vail you can't vail they can't vail	I can't be vailing you can't be vailing he can't be vailing we can't be vailing you can't be vailing they can't be vailing
Perfect	V-ing perfect
I can't have vailed you can't have vailed he can't have vailed we can't have vailed you can't have vailed they can't have vailed	I can't have been vailing you can't have been vailing he can't have been vailing we can't have been vailing you can't have been vailing they can't have been vailing

Interrogative form

Simple form	V-ing form
can I vail? can you vail? can he vail? can we vail? can you vail? can they vail?	can I be vailing? can you be vailing? can he be vailing? can we be vailing? can you be vailing? can they be vailing?
Perfect	V-ing perfect
can I have vailed? can you have vailed? can he have vailed? can we have vailed? can you have vailed? can they have vailed?	can I have been vailing? can you have been vailing? can he have been vailing? can we have been vailing? can you have been vailing? can they have been vailing?

Interro-negative form

Simple form	V-ing form
can't I vail? can't you vail? can't he vail? can't we vail? can't you vail? can't they vail?	can't I be vailing? can't you be vailing? can't he be vailing? can't we be vailing? can't you be vailing? can't they be vailing?
Perfect	V-ing perfect
can't I have vailed? can't you have vailed? can't he have vailed? can't we have vailed? can't you have vailed? can't they have vailed?	can't I have been vailing? can't you have been vailing? can't he have been vailing? can't we have been vailing? can't you have been vailing? can't they have been vailing?