must airmail
Verbo regular: airmail - airmailed- airmailed

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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	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	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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	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	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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? 	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? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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? 	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?