must hearken
Regular verb: hearken - hearkened- hearkened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must hearken
you must hearken
he must hearken
we must hearken
you must hearken
they must hearken 	I must be hearkening
you must be hearkening
he must be hearkening
we must be hearkening
you must be hearkening
they must be hearkening	I must have hearkened
you must have hearkened
he must have hearkened
we must have hearkened
you must have hearkened
they must have hearkened	I must have been hearkening
you must have been hearkening
he must have been hearkening
we must have been hearkening
you must have been hearkening
they must have been hearkening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not hearken
you must not hearken
he must not hearken
we must not hearken
you must not hearken
they must not hearken 	I must not be hearkening
you must not be hearkening
he must not be hearkening
we must not be hearkening
you must not be hearkening
they must not be hearkening	I must not have hearkened
you must not have hearkened
he must not have hearkened
we must not have hearkened
you must not have hearkened
they must not have hearkened	I must not have been hearkening
you must not have been hearkening
he must not have been hearkening
we must not have been hearkening
you must not have been hearkening
they must not have been hearkening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I hearken?
must you hearken?
must he hearken?
must we hearken?
must you hearken?
must they hearken? 	must I be hearkening?
must you be hearkening?
must he be hearkening?
must we be hearkening?
must you be hearkening?
must they be hearkening? 	must I have hearkened?
must you have hearkened?
must he have hearkened?
must we have hearkened?
must you have hearkened?
must they have hearkened? 	must I have been hearkening?
must you have been hearkening?
must he have been hearkening?
must we have been hearkening?
must you have been hearkening?
must they have been hearkening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not hearken?
must you not hearken?
must he not hearken?
must we not hearken?
must you not hearken?
must they not hearken? 	must I not be hearkening?
must you not be hearkening?
must he not be hearkening?
must we not be hearkening?
must you not be hearkening?
must they not be hearkening? 	must I not have hearkened?
must you not have hearkened?
must he not have hearkened?
must we not have hearkened?
must you not have hearkened?
must they not have hearkened? 	must I not have been hearkening?
must you not have been hearkening?
must he not have been hearkening?
must we not have been hearkening?
must you not have been hearkening?
must they not have been hearkening?