must double-lock
Regular verb: double-lock - double-locked- double-locked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must double-lock
you must double-lock
he must double-lock
we must double-lock
you must double-lock
they must double-lock 	I must be double-locking
you must be double-locking
he must be double-locking
we must be double-locking
you must be double-locking
they must be double-locking	I must have double-locked
you must have double-locked
he must have double-locked
we must have double-locked
you must have double-locked
they must have double-locked	I must have been double-locking
you must have been double-locking
he must have been double-locking
we must have been double-locking
you must have been double-locking
they must have been double-locking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not double-lock
you must not double-lock
he must not double-lock
we must not double-lock
you must not double-lock
they must not double-lock 	I must not be double-locking
you must not be double-locking
he must not be double-locking
we must not be double-locking
you must not be double-locking
they must not be double-locking	I must not have double-locked
you must not have double-locked
he must not have double-locked
we must not have double-locked
you must not have double-locked
they must not have double-locked	I must not have been double-locking
you must not have been double-locking
he must not have been double-locking
we must not have been double-locking
you must not have been double-locking
they must not have been double-locking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I double-lock?
must you double-lock?
must he double-lock?
must we double-lock?
must you double-lock?
must they double-lock? 	must I be double-locking?
must you be double-locking?
must he be double-locking?
must we be double-locking?
must you be double-locking?
must they be double-locking? 	must I have double-locked?
must you have double-locked?
must he have double-locked?
must we have double-locked?
must you have double-locked?
must they have double-locked? 	must I have been double-locking?
must you have been double-locking?
must he have been double-locking?
must we have been double-locking?
must you have been double-locking?
must they have been double-locking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not double-lock?
must you not double-lock?
must he not double-lock?
must we not double-lock?
must you not double-lock?
must they not double-lock? 	must I not be double-locking?
must you not be double-locking?
must he not be double-locking?
must we not be double-locking?
must you not be double-locking?
must they not be double-locking? 	must I not have double-locked?
must you not have double-locked?
must he not have double-locked?
must we not have double-locked?
must you not have double-locked?
must they not have double-locked? 	must I not have been double-locking?
must you not have been double-locking?
must he not have been double-locking?
must we not have been double-locking?
must you not have been double-locking?
must they not have been double-locking?