must gravel
Regular verb: gravel - gravelled- gravelled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must gravel
you must gravel
she must gravel
we must gravel
you must gravel
they must gravel 	I must be gravelling
you must be gravelling
she must be gravelling
we must be gravelling
you must be gravelling
they must be gravelling	I must have gravelled
you must have gravelled
she 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
she 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 must not gravel
you must not gravel
she must not gravel
we must not gravel
you must not gravel
they must not gravel 	I must not be gravelling
you must not be gravelling
she must not be gravelling
we must not be gravelling
you must not be gravelling
they must not be gravelling	I must not have gravelled
you must not have gravelled
she must not have gravelled
we must not have gravelled
you must not have gravelled
they must not have gravelled	I must not have been gravelling
you must not have been gravelling
she must not have been gravelling
we must not have been gravelling
you must not have been gravelling
they must not have been gravelling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I gravel?
must you gravel?
must she gravel?
must we gravel?
must you gravel?
must they gravel? 	must I be gravelling?
must you be gravelling?
must she be gravelling?
must we be gravelling?
must you be gravelling?
must they be gravelling? 	must I have gravelled?
must you have gravelled?
must she 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 she 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 	
must I not gravel?
must you not gravel?
must she not gravel?
must we not gravel?
must you not gravel?
must they not gravel? 	must I not be gravelling?
must you not be gravelling?
must she not be gravelling?
must we not be gravelling?
must you not be gravelling?
must they not be gravelling? 	must I not have gravelled?
must you not have gravelled?
must she not have gravelled?
must we not have gravelled?
must you not have gravelled?
must they not have gravelled? 	must I not have been gravelling?
must you not have been gravelling?
must she not have been gravelling?
must we not have been gravelling?
must you not have been gravelling?
must they not have been gravelling?