must heft
Regular verb: heft - hefted- hefted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must heft
you must heft
he must heft
we must heft
you must heft
they must heft 	I must be hefting
you must be hefting
he must be hefting
we must be hefting
you must be hefting
they must be hefting	I must have hefted
you must have hefted
he must have hefted
we must have hefted
you must have hefted
they must have hefted	I must have been hefting
you must have been hefting
he must have been hefting
we must have been hefting
you must have been hefting
they must have been hefting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't heft
you mustn't heft
he mustn't heft
we mustn't heft
you mustn't heft
they mustn't heft 	I mustn't be hefting
you mustn't be hefting
he mustn't be hefting
we mustn't be hefting
you mustn't be hefting
they mustn't be hefting	I mustn't have hefted
you mustn't have hefted
he mustn't have hefted
we mustn't have hefted
you mustn't have hefted
they mustn't have hefted	I mustn't have been hefting
you mustn't have been hefting
he mustn't have been hefting
we mustn't have been hefting
you mustn't have been hefting
they mustn't have been hefting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I heft?
must you heft?
must he heft?
must we heft?
must you heft?
must they heft? 	must I be hefting?
must you be hefting?
must he be hefting?
must we be hefting?
must you be hefting?
must they be hefting? 	must I have hefted?
must you have hefted?
must he have hefted?
must we have hefted?
must you have hefted?
must they have hefted? 	must I have been hefting?
must you have been hefting?
must he have been hefting?
must we have been hefting?
must you have been hefting?
must they have been hefting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I heft?
mustn't you heft?
mustn't he heft?
mustn't we heft?
mustn't you heft?
mustn't they heft? 	mustn't I be hefting?
mustn't you be hefting?
mustn't he be hefting?
mustn't we be hefting?
mustn't you be hefting?
mustn't they be hefting? 	mustn't I have hefted?
mustn't you have hefted?
mustn't he have hefted?
mustn't we have hefted?
mustn't you have hefted?
mustn't they have hefted? 	mustn't I have been hefting?
mustn't you have been hefting?
mustn't he have been hefting?
mustn't we have been hefting?
mustn't you have been hefting?
mustn't they have been hefting?