must perceive
Regular verb: perceive - perceived- perceived

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must perceive
you must perceive
he must perceive
we must perceive
you must perceive
they must perceive 	I must be perceiving
you must be perceiving
he must be perceiving
we must be perceiving
you must be perceiving
they must be perceiving	I must have perceived
you must have perceived
he must have perceived
we must have perceived
you must have perceived
they must have perceived	I must have been perceiving
you must have been perceiving
he must have been perceiving
we must have been perceiving
you must have been perceiving
they must have been perceiving	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not perceive
you must not perceive
he must not perceive
we must not perceive
you must not perceive
they must not perceive 	I must not be perceiving
you must not be perceiving
he must not be perceiving
we must not be perceiving
you must not be perceiving
they must not be perceiving	I must not have perceived
you must not have perceived
he must not have perceived
we must not have perceived
you must not have perceived
they must not have perceived	I must not have been perceiving
you must not have been perceiving
he must not have been perceiving
we must not have been perceiving
you must not have been perceiving
they must not have been perceiving	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I perceive?
must you perceive?
must he perceive?
must we perceive?
must you perceive?
must they perceive? 	must I be perceiving?
must you be perceiving?
must he be perceiving?
must we be perceiving?
must you be perceiving?
must they be perceiving? 	must I have perceived?
must you have perceived?
must he have perceived?
must we have perceived?
must you have perceived?
must they have perceived? 	must I have been perceiving?
must you have been perceiving?
must he have been perceiving?
must we have been perceiving?
must you have been perceiving?
must they have been perceiving? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not perceive?
must you not perceive?
must he not perceive?
must we not perceive?
must you not perceive?
must they not perceive? 	must I not be perceiving?
must you not be perceiving?
must he not be perceiving?
must we not be perceiving?
must you not be perceiving?
must they not be perceiving? 	must I not have perceived?
must you not have perceived?
must he not have perceived?
must we not have perceived?
must you not have perceived?
must they not have perceived? 	must I not have been perceiving?
must you not have been perceiving?
must he not have been perceiving?
must we not have been perceiving?
must you not have been perceiving?
must they not have been perceiving?