must gravel
Regular verb: gravel - gravelled- gravelled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must gravel
you must gravel
he must gravel
we must gravel
you must gravel
they must gravel 	I must be gravelling
you must be gravelling
he must be gravelling
we must be gravelling
you must be gravelling
they must be gravelling	I must have gravelled
you must have gravelled
he must have gravelled
we must have gravelled
you must have gravelled
they must have gravelled	I must have been gravelling
you must have been gravelling
he must have been gravelling
we must have been gravelling
you must have been gravelling
they must have been gravelling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't gravel
you mustn't gravel
he mustn't gravel
we mustn't gravel
you mustn't gravel
they mustn't gravel 	I mustn't be gravelling
you mustn't be gravelling
he mustn't be gravelling
we mustn't be gravelling
you mustn't be gravelling
they mustn't be gravelling	I mustn't have gravelled
you mustn't have gravelled
he mustn't have gravelled
we mustn't have gravelled
you mustn't have gravelled
they mustn't have gravelled	I mustn't have been gravelling
you mustn't have been gravelling
he mustn't have been gravelling
we mustn't have been gravelling
you mustn't have been gravelling
they mustn't have been gravelling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I gravel?
must you gravel?
must he gravel?
must we gravel?
must you gravel?
must they gravel? 	must I be gravelling?
must you be gravelling?
must he be gravelling?
must we be gravelling?
must you be gravelling?
must they be gravelling? 	must I have gravelled?
must you have gravelled?
must he have gravelled?
must we have gravelled?
must you have gravelled?
must they have gravelled? 	must I have been gravelling?
must you have been gravelling?
must he have been gravelling?
must we have been gravelling?
must you have been gravelling?
must they have been gravelling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I gravel?
mustn't you gravel?
mustn't he gravel?
mustn't we gravel?
mustn't you gravel?
mustn't they gravel? 	mustn't I be gravelling?
mustn't you be gravelling?
mustn't he be gravelling?
mustn't we be gravelling?
mustn't you be gravelling?
mustn't they be gravelling? 	mustn't I have gravelled?
mustn't you have gravelled?
mustn't he have gravelled?
mustn't we have gravelled?
mustn't you have gravelled?
mustn't they have gravelled? 	mustn't I have been gravelling?
mustn't you have been gravelling?
mustn't he have been gravelling?
mustn't we have been gravelling?
mustn't you have been gravelling?
mustn't they have been gravelling?