English verb conjugation
MUST AIRMAIL

Regular verb: airmail - airmailed - airmailed

Affirmation

Simple form	V-ing form
I must airmail you must airmail he must airmail we must airmail you must airmail they must airmail	I must be airmailing you must be airmailing he must be airmailing we must be airmailing you must be airmailing they must be airmailing
Perfect	V-ing perfect
I must have airmailed you must have airmailed he must have airmailed we must have airmailed you must have airmailed they must have airmailed	I must have been airmailing you must have been airmailing he must have been airmailing we must have been airmailing you must have been airmailing they must have been airmailing

Negation

Simple form	V-ing form
I must not airmail you must not airmail he must not airmail we must not airmail you must not airmail they must not airmail	I must not be airmailing you must not be airmailing he must not be airmailing we must not be airmailing you must not be airmailing they must not be airmailing
Perfect	V-ing perfect
I must not have airmailed you must not have airmailed he must not have airmailed we must not have airmailed you must not have airmailed they must not have airmailed	I must not have been airmailing you must not have been airmailing he must not have been airmailing we must not have been airmailing you must not have been airmailing they must not have been airmailing

Interrogative form

Simple form	V-ing form
must I airmail? must you airmail? must he airmail? must we airmail? must you airmail? must they airmail?	must I be airmailing? must you be airmailing? must he be airmailing? must we be airmailing? must you be airmailing? must they be airmailing?
Perfect	V-ing perfect
must I have airmailed? must you have airmailed? must he have airmailed? must we have airmailed? must you have airmailed? must they have airmailed?	must I have been airmailing? must you have been airmailing? must he have been airmailing? must we have been airmailing? must you have been airmailing? must they have been airmailing?

Interro-negative form

Simple form	V-ing form
must I not airmail? must you not airmail? must he not airmail? must we not airmail? must you not airmail? must they not airmail?	must I not be airmailing? must you not be airmailing? must he not be airmailing? must we not be airmailing? must you not be airmailing? must they not be airmailing?
Perfect	V-ing perfect
must I not have airmailed? must you not have airmailed? must he not have airmailed? must we not have airmailed? must you not have airmailed? must they not have airmailed?	must I not have been airmailing? must you not have been airmailing? must he not have been airmailing? must we not have been airmailing? must you not have been airmailing? must they not have been airmailing?