must tunnel
Regular verb: tunnel - tunnelled- tunnelled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must tunnel
you must tunnel
he must tunnel
we must tunnel
you must tunnel
they must tunnel 	I must be tunnelling
you must be tunnelling
he must be tunnelling
we must be tunnelling
you must be tunnelling
they must be tunnelling	I must have tunnelled
you must have tunnelled
he must have tunnelled
we must have tunnelled
you must have tunnelled
they must have tunnelled	I must have been tunnelling
you must have been tunnelling
he must have been tunnelling
we must have been tunnelling
you must have been tunnelling
they must have been tunnelling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't tunnel
you mustn't tunnel
he mustn't tunnel
we mustn't tunnel
you mustn't tunnel
they mustn't tunnel 	I mustn't be tunnelling
you mustn't be tunnelling
he mustn't be tunnelling
we mustn't be tunnelling
you mustn't be tunnelling
they mustn't be tunnelling	I mustn't have tunnelled
you mustn't have tunnelled
he mustn't have tunnelled
we mustn't have tunnelled
you mustn't have tunnelled
they mustn't have tunnelled	I mustn't have been tunnelling
you mustn't have been tunnelling
he mustn't have been tunnelling
we mustn't have been tunnelling
you mustn't have been tunnelling
they mustn't have been tunnelling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I tunnel?
must you tunnel?
must he tunnel?
must we tunnel?
must you tunnel?
must they tunnel? 	must I be tunnelling?
must you be tunnelling?
must he be tunnelling?
must we be tunnelling?
must you be tunnelling?
must they be tunnelling? 	must I have tunnelled?
must you have tunnelled?
must he have tunnelled?
must we have tunnelled?
must you have tunnelled?
must they have tunnelled? 	must I have been tunnelling?
must you have been tunnelling?
must he have been tunnelling?
must we have been tunnelling?
must you have been tunnelling?
must they have been tunnelling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I tunnel?
mustn't you tunnel?
mustn't he tunnel?
mustn't we tunnel?
mustn't you tunnel?
mustn't they tunnel? 	mustn't I be tunnelling?
mustn't you be tunnelling?
mustn't he be tunnelling?
mustn't we be tunnelling?
mustn't you be tunnelling?
mustn't they be tunnelling? 	mustn't I have tunnelled?
mustn't you have tunnelled?
mustn't he have tunnelled?
mustn't we have tunnelled?
mustn't you have tunnelled?
mustn't they have tunnelled? 	mustn't I have been tunnelling?
mustn't you have been tunnelling?
mustn't he have been tunnelling?
mustn't we have been tunnelling?
mustn't you have been tunnelling?
mustn't they have been tunnelling?