must culture
Regular verb: culture - cultured- cultured

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must culture
you must culture
he must culture
we must culture
you must culture
they must culture 	I must be culturing
you must be culturing
he must be culturing
we must be culturing
you must be culturing
they must be culturing	I must have cultured
you must have cultured
he must have cultured
we must have cultured
you must have cultured
they must have cultured	I must have been culturing
you must have been culturing
he must have been culturing
we must have been culturing
you must have been culturing
they must have been culturing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not culture
you must not culture
he must not culture
we must not culture
you must not culture
they must not culture 	I must not be culturing
you must not be culturing
he must not be culturing
we must not be culturing
you must not be culturing
they must not be culturing	I must not have cultured
you must not have cultured
he must not have cultured
we must not have cultured
you must not have cultured
they must not have cultured	I must not have been culturing
you must not have been culturing
he must not have been culturing
we must not have been culturing
you must not have been culturing
they must not have been culturing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I culture?
must you culture?
must he culture?
must we culture?
must you culture?
must they culture? 	must I be culturing?
must you be culturing?
must he be culturing?
must we be culturing?
must you be culturing?
must they be culturing? 	must I have cultured?
must you have cultured?
must he have cultured?
must we have cultured?
must you have cultured?
must they have cultured? 	must I have been culturing?
must you have been culturing?
must he have been culturing?
must we have been culturing?
must you have been culturing?
must they have been culturing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not culture?
must you not culture?
must he not culture?
must we not culture?
must you not culture?
must they not culture? 	must I not be culturing?
must you not be culturing?
must he not be culturing?
must we not be culturing?
must you not be culturing?
must they not be culturing? 	must I not have cultured?
must you not have cultured?
must he not have cultured?
must we not have cultured?
must you not have cultured?
must they not have cultured? 	must I not have been culturing?
must you not have been culturing?
must he not have been culturing?
must we not have been culturing?
must you not have been culturing?
must they not have been culturing?