must decalcify
Regular verb: decalcify - decalcified- decalcified

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must decalcify
you must decalcify
he must decalcify
we must decalcify
you must decalcify
they must decalcify 	I must be decalcifying
you must be decalcifying
he must be decalcifying
we must be decalcifying
you must be decalcifying
they must be decalcifying	I must have decalcified
you must have decalcified
he must have decalcified
we must have decalcified
you must have decalcified
they must have decalcified	I must have been decalcifying
you must have been decalcifying
he must have been decalcifying
we must have been decalcifying
you must have been decalcifying
they must have been decalcifying	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not decalcify
you must not decalcify
he must not decalcify
we must not decalcify
you must not decalcify
they must not decalcify 	I must not be decalcifying
you must not be decalcifying
he must not be decalcifying
we must not be decalcifying
you must not be decalcifying
they must not be decalcifying	I must not have decalcified
you must not have decalcified
he must not have decalcified
we must not have decalcified
you must not have decalcified
they must not have decalcified	I must not have been decalcifying
you must not have been decalcifying
he must not have been decalcifying
we must not have been decalcifying
you must not have been decalcifying
they must not have been decalcifying	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I decalcify?
must you decalcify?
must he decalcify?
must we decalcify?
must you decalcify?
must they decalcify? 	must I be decalcifying?
must you be decalcifying?
must he be decalcifying?
must we be decalcifying?
must you be decalcifying?
must they be decalcifying? 	must I have decalcified?
must you have decalcified?
must he have decalcified?
must we have decalcified?
must you have decalcified?
must they have decalcified? 	must I have been decalcifying?
must you have been decalcifying?
must he have been decalcifying?
must we have been decalcifying?
must you have been decalcifying?
must they have been decalcifying? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not decalcify?
must you not decalcify?
must he not decalcify?
must we not decalcify?
must you not decalcify?
must they not decalcify? 	must I not be decalcifying?
must you not be decalcifying?
must he not be decalcifying?
must we not be decalcifying?
must you not be decalcifying?
must they not be decalcifying? 	must I not have decalcified?
must you not have decalcified?
must he not have decalcified?
must we not have decalcified?
must you not have decalcified?
must they not have decalcified? 	must I not have been decalcifying?
must you not have been decalcifying?
must he not have been decalcifying?
must we not have been decalcifying?
must you not have been decalcifying?
must they not have been decalcifying?