must drill
Regular verb: drill - drilled- drilled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must drill
you must drill
he must drill
we must drill
you must drill
they must drill 	I must be drilling
you must be drilling
he must be drilling
we must be drilling
you must be drilling
they must be drilling	I must have drilled
you must have drilled
he must have drilled
we must have drilled
you must have drilled
they must have drilled	I must have been drilling
you must have been drilling
he must have been drilling
we must have been drilling
you must have been drilling
they must have been drilling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't drill
you mustn't drill
he mustn't drill
we mustn't drill
you mustn't drill
they mustn't drill 	I mustn't be drilling
you mustn't be drilling
he mustn't be drilling
we mustn't be drilling
you mustn't be drilling
they mustn't be drilling	I mustn't have drilled
you mustn't have drilled
he mustn't have drilled
we mustn't have drilled
you mustn't have drilled
they mustn't have drilled	I mustn't have been drilling
you mustn't have been drilling
he mustn't have been drilling
we mustn't have been drilling
you mustn't have been drilling
they mustn't have been drilling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I drill?
must you drill?
must he drill?
must we drill?
must you drill?
must they drill? 	must I be drilling?
must you be drilling?
must he be drilling?
must we be drilling?
must you be drilling?
must they be drilling? 	must I have drilled?
must you have drilled?
must he have drilled?
must we have drilled?
must you have drilled?
must they have drilled? 	must I have been drilling?
must you have been drilling?
must he have been drilling?
must we have been drilling?
must you have been drilling?
must they have been drilling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I drill?
mustn't you drill?
mustn't he drill?
mustn't we drill?
mustn't you drill?
mustn't they drill? 	mustn't I be drilling?
mustn't you be drilling?
mustn't he be drilling?
mustn't we be drilling?
mustn't you be drilling?
mustn't they be drilling? 	mustn't I have drilled?
mustn't you have drilled?
mustn't he have drilled?
mustn't we have drilled?
mustn't you have drilled?
mustn't they have drilled? 	mustn't I have been drilling?
mustn't you have been drilling?
mustn't he have been drilling?
mustn't we have been drilling?
mustn't you have been drilling?
mustn't they have been drilling?