could ail
Regular verb: ail - ailed- ailed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
I could not ail
you could not ail
she could not ail
we could not ail
you could not ail
they could not ail 	I could not be ailing
you could not be ailing
she could not be ailing
we could not be ailing
you could not be ailing
they could not be ailing	I could not have ailed
you could not have ailed
she could not have ailed
we could not have ailed
you could not have ailed
they could not have ailed	I could not have been ailing
you could not have been ailing
she could not have been ailing
we could not have been ailing
you could not have been ailing
they could not have been ailing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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? 	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 	Perfect 	V-ing perfect 	
could I not ail?
could you not ail?
could she not ail?
could we not ail?
could you not ail?
could they not ail? 	could I not be ailing?
could you not be ailing?
could she not be ailing?
could we not be ailing?
could you not be ailing?
could they not be ailing? 	could I not have ailed?
could you not have ailed?
could she not have ailed?
could we not have ailed?
could you not have ailed?
could they not have ailed? 	could I not have been ailing?
could you not have been ailing?
could she not have been ailing?
could we not have been ailing?
could you not have been ailing?
could they not have been ailing?