must half-mast
Regular verb: half-mast - half-masted- half-masted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must half-mast
you must half-mast
he must half-mast
we must half-mast
you must half-mast
they must half-mast 	I must be half-masting
you must be half-masting
he must be half-masting
we must be half-masting
you must be half-masting
they must be half-masting	I must have half-masted
you must have half-masted
he must have half-masted
we must have half-masted
you must have half-masted
they must have half-masted	I must have been half-masting
you must have been half-masting
he must have been half-masting
we must have been half-masting
you must have been half-masting
they must have been half-masting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't half-mast
you mustn't half-mast
he mustn't half-mast
we mustn't half-mast
you mustn't half-mast
they mustn't half-mast 	I mustn't be half-masting
you mustn't be half-masting
he mustn't be half-masting
we mustn't be half-masting
you mustn't be half-masting
they mustn't be half-masting	I mustn't have half-masted
you mustn't have half-masted
he mustn't have half-masted
we mustn't have half-masted
you mustn't have half-masted
they mustn't have half-masted	I mustn't have been half-masting
you mustn't have been half-masting
he mustn't have been half-masting
we mustn't have been half-masting
you mustn't have been half-masting
they mustn't have been half-masting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I half-mast?
must you half-mast?
must he half-mast?
must we half-mast?
must you half-mast?
must they half-mast? 	must I be half-masting?
must you be half-masting?
must he be half-masting?
must we be half-masting?
must you be half-masting?
must they be half-masting? 	must I have half-masted?
must you have half-masted?
must he have half-masted?
must we have half-masted?
must you have half-masted?
must they have half-masted? 	must I have been half-masting?
must you have been half-masting?
must he have been half-masting?
must we have been half-masting?
must you have been half-masting?
must they have been half-masting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I half-mast?
mustn't you half-mast?
mustn't he half-mast?
mustn't we half-mast?
mustn't you half-mast?
mustn't they half-mast? 	mustn't I be half-masting?
mustn't you be half-masting?
mustn't he be half-masting?
mustn't we be half-masting?
mustn't you be half-masting?
mustn't they be half-masting? 	mustn't I have half-masted?
mustn't you have half-masted?
mustn't he have half-masted?
mustn't we have half-masted?
mustn't you have half-masted?
mustn't they have half-masted? 	mustn't I have been half-masting?
mustn't you have been half-masting?
mustn't he have been half-masting?
mustn't we have been half-masting?
mustn't you have been half-masting?
mustn't they have been half-masting?