I can ail you can ail he can ail we can ail you can ail they can ail
V-ing form
I can be ailing you can be ailing he can be ailing we can be ailing you can be ailing they can be ailing
Perfect
I can have ailed you can have ailed he can have ailed we can have ailed you can have ailed they can have ailed
V-ing perfect
I can have been ailing you can have been ailing he can have been ailing we can have been ailing you can have been ailing they can have been ailing
Negation
Simple form
I can't ail you can't ail he can't ail we can't ail you can't ail they can't ail
V-ing form
I can't be ailing you can't be ailing he can't be ailing we can't be ailing you can't be ailing they can't be ailing
Perfect
I can't have ailed you can't have ailed he can't have ailed we can't have ailed you can't have ailed they can't have ailed
V-ing perfect
I can't have been ailing you can't have been ailing he can't have been ailing we can't have been ailing you can't have been ailing they can't have been ailing
Interrogative form
Simple form
can I ail? can you ail? can he ail? can we ail? can you ail? can they ail?
V-ing form
can I be ailing? can you be ailing? can he be ailing? can we be ailing? can you be ailing? can they be ailing?
Perfect
can I have ailed? can you have ailed? can he have ailed? can we have ailed? can you have ailed? can they have ailed?
V-ing perfect
can I have been ailing? can you have been ailing? can he have been ailing? can we have been ailing? can you have been ailing? can they have been ailing?
Interro-negative form
Simple form
can't I ail? can't you ail? can't he ail? can't we ail? can't you ail? can't they ail?
V-ing form
can't I be ailing? can't you be ailing? can't he be ailing? can't we be ailing? can't you be ailing? can't they be ailing?
Perfect
can't I have ailed? can't you have ailed? can't he have ailed? can't we have ailed? can't you have ailed? can't they have ailed?
V-ing perfect
can't I have been ailing? can't you have been ailing? can't he have been ailing? can't we have been ailing? can't you have been ailing? can't they have been ailing?