must hark
Regular verb: hark - harked- harked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must hark
you must hark
he must hark
we must hark
you must hark
they must hark 	I must be harking
you must be harking
he must be harking
we must be harking
you must be harking
they must be harking	I must have harked
you must have harked
he must have harked
we must have harked
you must have harked
they must have harked	I must have been harking
you must have been harking
he must have been harking
we must have been harking
you must have been harking
they must have been harking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not hark
you must not hark
he must not hark
we must not hark
you must not hark
they must not hark 	I must not be harking
you must not be harking
he must not be harking
we must not be harking
you must not be harking
they must not be harking	I must not have harked
you must not have harked
he must not have harked
we must not have harked
you must not have harked
they must not have harked	I must not have been harking
you must not have been harking
he must not have been harking
we must not have been harking
you must not have been harking
they must not have been harking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I hark?
must you hark?
must he hark?
must we hark?
must you hark?
must they hark? 	must I be harking?
must you be harking?
must he be harking?
must we be harking?
must you be harking?
must they be harking? 	must I have harked?
must you have harked?
must he have harked?
must we have harked?
must you have harked?
must they have harked? 	must I have been harking?
must you have been harking?
must he have been harking?
must we have been harking?
must you have been harking?
must they have been harking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not hark?
must you not hark?
must he not hark?
must we not hark?
must you not hark?
must they not hark? 	must I not be harking?
must you not be harking?
must he not be harking?
must we not be harking?
must you not be harking?
must they not be harking? 	must I not have harked?
must you not have harked?
must he not have harked?
must we not have harked?
must you not have harked?
must they not have harked? 	must I not have been harking?
must you not have been harking?
must he not have been harking?
must we not have been harking?
must you not have been harking?
must they not have been harking?