English verb conjugation
COULD AIL

Regular verb: ail - ailed - ailed

Affirmation

Simple form	V-ing form
I could ail you could ail she could ail we could ail you could ail they could ail	I could be ailing you could be ailing she could be ailing we could be ailing you could be ailing they could be ailing
Perfect	V-ing perfect
I could have ailed you could have ailed she could have ailed we could have ailed you could have ailed they could have ailed	I could have been ailing you could have been ailing she could have been ailing we could have been ailing you could have been ailing they could have been ailing

Negation

Simple form	V-ing form
I couldn't ail you couldn't ail she couldn't ail we couldn't ail you couldn't ail they couldn't ail	I couldn't be ailing you couldn't be ailing she couldn't be ailing we couldn't be ailing you couldn't be ailing they couldn't be ailing
Perfect	V-ing perfect
I couldn't have ailed you couldn't have ailed she couldn't have ailed we couldn't have ailed you couldn't have ailed they couldn't have ailed	I couldn't have been ailing you couldn't have been ailing she couldn't have been ailing we couldn't have been ailing you couldn't have been ailing they couldn't have been ailing

Interrogative form

Simple form	V-ing form
could I ail? could you ail? could she ail? could we ail? could you ail? could they ail?	could I be ailing? could you be ailing? could she be ailing? could we be ailing? could you be ailing? could they be ailing?
Perfect	V-ing perfect
could I have ailed? could you have ailed? could she have ailed? could we have ailed? could you have ailed? could they have ailed?	could I have been ailing? could you have been ailing? could she have been ailing? could we have been ailing? could you have been ailing? could they have been ailing?

Interro-negative form

Simple form	V-ing form
couldn't I ail? couldn't you ail? couldn't she ail? couldn't we ail? couldn't you ail? couldn't they ail?	couldn't I be ailing? couldn't you be ailing? couldn't she be ailing? couldn't we be ailing? couldn't you be ailing? couldn't they be ailing?
Perfect	V-ing perfect
couldn't I have ailed? couldn't you have ailed? couldn't she have ailed? couldn't we have ailed? couldn't you have ailed? couldn't they have ailed?	couldn't I have been ailing? couldn't you have been ailing? couldn't she have been ailing? couldn't we have been ailing? couldn't you have been ailing? couldn't they have been ailing?