must drill
Regular verb: drill - drilled- drilled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must drill
you must drill
she must drill
we must drill
you must drill
they must drill 	I must be drilling
you must be drilling
she must be drilling
we must be drilling
you must be drilling
they must be drilling	I must have drilled
you must have drilled
she 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
she 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
she 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
she 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
she 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
she 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 she drill?
must we drill?
must you drill?
must they drill? 	must I be drilling?
must you be drilling?
must she be drilling?
must we be drilling?
must you be drilling?
must they be drilling? 	must I have drilled?
must you have drilled?
must she 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 she 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 she 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 she 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 she 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 she have been drilling?
mustn't we have been drilling?
mustn't you have been drilling?
mustn't they have been drilling?