must apprehend
Regular verb: apprehend - apprehended- apprehended

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must apprehend
you must apprehend
he must apprehend
we must apprehend
you must apprehend
they must apprehend 	I must be apprehending
you must be apprehending
he must be apprehending
we must be apprehending
you must be apprehending
they must be apprehending	I must have apprehended
you must have apprehended
he must have apprehended
we must have apprehended
you must have apprehended
they must have apprehended	I must have been apprehending
you must have been apprehending
he must have been apprehending
we must have been apprehending
you must have been apprehending
they must have been apprehending	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't apprehend
you mustn't apprehend
he mustn't apprehend
we mustn't apprehend
you mustn't apprehend
they mustn't apprehend 	I mustn't be apprehending
you mustn't be apprehending
he mustn't be apprehending
we mustn't be apprehending
you mustn't be apprehending
they mustn't be apprehending	I mustn't have apprehended
you mustn't have apprehended
he mustn't have apprehended
we mustn't have apprehended
you mustn't have apprehended
they mustn't have apprehended	I mustn't have been apprehending
you mustn't have been apprehending
he mustn't have been apprehending
we mustn't have been apprehending
you mustn't have been apprehending
they mustn't have been apprehending	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I apprehend?
must you apprehend?
must he apprehend?
must we apprehend?
must you apprehend?
must they apprehend? 	must I be apprehending?
must you be apprehending?
must he be apprehending?
must we be apprehending?
must you be apprehending?
must they be apprehending? 	must I have apprehended?
must you have apprehended?
must he have apprehended?
must we have apprehended?
must you have apprehended?
must they have apprehended? 	must I have been apprehending?
must you have been apprehending?
must he have been apprehending?
must we have been apprehending?
must you have been apprehending?
must they have been apprehending? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I apprehend?
mustn't you apprehend?
mustn't he apprehend?
mustn't we apprehend?
mustn't you apprehend?
mustn't they apprehend? 	mustn't I be apprehending?
mustn't you be apprehending?
mustn't he be apprehending?
mustn't we be apprehending?
mustn't you be apprehending?
mustn't they be apprehending? 	mustn't I have apprehended?
mustn't you have apprehended?
mustn't he have apprehended?
mustn't we have apprehended?
mustn't you have apprehended?
mustn't they have apprehended? 	mustn't I have been apprehending?
mustn't you have been apprehending?
mustn't he have been apprehending?
mustn't we have been apprehending?
mustn't you have been apprehending?
mustn't they have been apprehending?