must preen
Regular verb: preen - preened- preened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must preen
you must preen
he must preen
we must preen
you must preen
they must preen 	I must be preening
you must be preening
he must be preening
we must be preening
you must be preening
they must be preening	I must have preened
you must have preened
he must have preened
we must have preened
you must have preened
they must have preened	I must have been preening
you must have been preening
he must have been preening
we must have been preening
you must have been preening
they must have been preening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not preen
you must not preen
he must not preen
we must not preen
you must not preen
they must not preen 	I must not be preening
you must not be preening
he must not be preening
we must not be preening
you must not be preening
they must not be preening	I must not have preened
you must not have preened
he must not have preened
we must not have preened
you must not have preened
they must not have preened	I must not have been preening
you must not have been preening
he must not have been preening
we must not have been preening
you must not have been preening
they must not have been preening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I preen?
must you preen?
must he preen?
must we preen?
must you preen?
must they preen? 	must I be preening?
must you be preening?
must he be preening?
must we be preening?
must you be preening?
must they be preening? 	must I have preened?
must you have preened?
must he have preened?
must we have preened?
must you have preened?
must they have preened? 	must I have been preening?
must you have been preening?
must he have been preening?
must we have been preening?
must you have been preening?
must they have been preening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not preen?
must you not preen?
must he not preen?
must we not preen?
must you not preen?
must they not preen? 	must I not be preening?
must you not be preening?
must he not be preening?
must we not be preening?
must you not be preening?
must they not be preening? 	must I not have preened?
must you not have preened?
must he not have preened?
must we not have preened?
must you not have preened?
must they not have preened? 	must I not have been preening?
must you not have been preening?
must he not have been preening?
must we not have been preening?
must you not have been preening?
must they not have been preening?