must ail
Regular verb: ail - ailed- ailed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must ail
you must ail
he must ail
we must ail
you must ail
they must ail 	I must be ailing
you must be ailing
he must be ailing
we must be ailing
you must be ailing
they must be ailing	I must have ailed
you must have ailed
he must have ailed
we must have ailed
you must have ailed
they must have ailed	I must have been ailing
you must have been ailing
he must have been ailing
we must have been ailing
you must have been ailing
they must have been ailing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not ail
you must not ail
he must not ail
we must not ail
you must not ail
they must not ail 	I must not be ailing
you must not be ailing
he must not be ailing
we must not be ailing
you must not be ailing
they must not be ailing	I must not have ailed
you must not have ailed
he must not have ailed
we must not have ailed
you must not have ailed
they must not have ailed	I must not have been ailing
you must not have been ailing
he must not have been ailing
we must not have been ailing
you must not have been ailing
they must not have been ailing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I ail?
must you ail?
must he ail?
must we ail?
must you ail?
must they ail? 	must I be ailing?
must you be ailing?
must he be ailing?
must we be ailing?
must you be ailing?
must they be ailing? 	must I have ailed?
must you have ailed?
must he have ailed?
must we have ailed?
must you have ailed?
must they have ailed? 	must I have been ailing?
must you have been ailing?
must he have been ailing?
must we have been ailing?
must you have been ailing?
must they have been ailing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not ail?
must you not ail?
must he not ail?
must we not ail?
must you not ail?
must they not ail? 	must I not be ailing?
must you not be ailing?
must he not be ailing?
must we not be ailing?
must you not be ailing?
must they not be ailing? 	must I not have ailed?
must you not have ailed?
must he not have ailed?
must we not have ailed?
must you not have ailed?
must they not have ailed? 	must I not have been ailing?
must you not have been ailing?
must he not have been ailing?
must we not have been ailing?
must you not have been ailing?
must they not have been ailing?