must overstaff
Regular verb: overstaff - overstaffed- overstaffed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must overstaff
you must overstaff
he must overstaff
we must overstaff
you must overstaff
they must overstaff 	I must be overstaffing
you must be overstaffing
he must be overstaffing
we must be overstaffing
you must be overstaffing
they must be overstaffing	I must have overstaffed
you must have overstaffed
he must have overstaffed
we must have overstaffed
you must have overstaffed
they must have overstaffed	I must have been overstaffing
you must have been overstaffing
he must have been overstaffing
we must have been overstaffing
you must have been overstaffing
they must have been overstaffing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not overstaff
you must not overstaff
he must not overstaff
we must not overstaff
you must not overstaff
they must not overstaff 	I must not be overstaffing
you must not be overstaffing
he must not be overstaffing
we must not be overstaffing
you must not be overstaffing
they must not be overstaffing	I must not have overstaffed
you must not have overstaffed
he must not have overstaffed
we must not have overstaffed
you must not have overstaffed
they must not have overstaffed	I must not have been overstaffing
you must not have been overstaffing
he must not have been overstaffing
we must not have been overstaffing
you must not have been overstaffing
they must not have been overstaffing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I overstaff?
must you overstaff?
must he overstaff?
must we overstaff?
must you overstaff?
must they overstaff? 	must I be overstaffing?
must you be overstaffing?
must he be overstaffing?
must we be overstaffing?
must you be overstaffing?
must they be overstaffing? 	must I have overstaffed?
must you have overstaffed?
must he have overstaffed?
must we have overstaffed?
must you have overstaffed?
must they have overstaffed? 	must I have been overstaffing?
must you have been overstaffing?
must he have been overstaffing?
must we have been overstaffing?
must you have been overstaffing?
must they have been overstaffing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not overstaff?
must you not overstaff?
must he not overstaff?
must we not overstaff?
must you not overstaff?
must they not overstaff? 	must I not be overstaffing?
must you not be overstaffing?
must he not be overstaffing?
must we not be overstaffing?
must you not be overstaffing?
must they not be overstaffing? 	must I not have overstaffed?
must you not have overstaffed?
must he not have overstaffed?
must we not have overstaffed?
must you not have overstaffed?
must they not have overstaffed? 	must I not have been overstaffing?
must you not have been overstaffing?
must he not have been overstaffing?
must we not have been overstaffing?
must you not have been overstaffing?
must they not have been overstaffing?