must postmark
Regular verb: postmark - postmarked- postmarked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must postmark
you must postmark
he must postmark
we must postmark
you must postmark
they must postmark 	I must be postmarking
you must be postmarking
he must be postmarking
we must be postmarking
you must be postmarking
they must be postmarking	I must have postmarked
you must have postmarked
he must have postmarked
we must have postmarked
you must have postmarked
they must have postmarked	I must have been postmarking
you must have been postmarking
he must have been postmarking
we must have been postmarking
you must have been postmarking
they must have been postmarking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not postmark
you must not postmark
he must not postmark
we must not postmark
you must not postmark
they must not postmark 	I must not be postmarking
you must not be postmarking
he must not be postmarking
we must not be postmarking
you must not be postmarking
they must not be postmarking	I must not have postmarked
you must not have postmarked
he must not have postmarked
we must not have postmarked
you must not have postmarked
they must not have postmarked	I must not have been postmarking
you must not have been postmarking
he must not have been postmarking
we must not have been postmarking
you must not have been postmarking
they must not have been postmarking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I postmark?
must you postmark?
must he postmark?
must we postmark?
must you postmark?
must they postmark? 	must I be postmarking?
must you be postmarking?
must he be postmarking?
must we be postmarking?
must you be postmarking?
must they be postmarking? 	must I have postmarked?
must you have postmarked?
must he have postmarked?
must we have postmarked?
must you have postmarked?
must they have postmarked? 	must I have been postmarking?
must you have been postmarking?
must he have been postmarking?
must we have been postmarking?
must you have been postmarking?
must they have been postmarking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not postmark?
must you not postmark?
must he not postmark?
must we not postmark?
must you not postmark?
must they not postmark? 	must I not be postmarking?
must you not be postmarking?
must he not be postmarking?
must we not be postmarking?
must you not be postmarking?
must they not be postmarking? 	must I not have postmarked?
must you not have postmarked?
must he not have postmarked?
must we not have postmarked?
must you not have postmarked?
must they not have postmarked? 	must I not have been postmarking?
must you not have been postmarking?
must he not have been postmarking?
must we not have been postmarking?
must you not have been postmarking?
must they not have been postmarking?