must precondition
Regular verb: precondition - preconditioned- preconditioned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must precondition
you must precondition
he must precondition
we must precondition
you must precondition
they must precondition 	I must be preconditioning
you must be preconditioning
he must be preconditioning
we must be preconditioning
you must be preconditioning
they must be preconditioning	I must have preconditioned
you must have preconditioned
he must have preconditioned
we must have preconditioned
you must have preconditioned
they must have preconditioned	I must have been preconditioning
you must have been preconditioning
he must have been preconditioning
we must have been preconditioning
you must have been preconditioning
they must have been preconditioning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not precondition
you must not precondition
he must not precondition
we must not precondition
you must not precondition
they must not precondition 	I must not be preconditioning
you must not be preconditioning
he must not be preconditioning
we must not be preconditioning
you must not be preconditioning
they must not be preconditioning	I must not have preconditioned
you must not have preconditioned
he must not have preconditioned
we must not have preconditioned
you must not have preconditioned
they must not have preconditioned	I must not have been preconditioning
you must not have been preconditioning
he must not have been preconditioning
we must not have been preconditioning
you must not have been preconditioning
they must not have been preconditioning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I precondition?
must you precondition?
must he precondition?
must we precondition?
must you precondition?
must they precondition? 	must I be preconditioning?
must you be preconditioning?
must he be preconditioning?
must we be preconditioning?
must you be preconditioning?
must they be preconditioning? 	must I have preconditioned?
must you have preconditioned?
must he have preconditioned?
must we have preconditioned?
must you have preconditioned?
must they have preconditioned? 	must I have been preconditioning?
must you have been preconditioning?
must he have been preconditioning?
must we have been preconditioning?
must you have been preconditioning?
must they have been preconditioning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not precondition?
must you not precondition?
must he not precondition?
must we not precondition?
must you not precondition?
must they not precondition? 	must I not be preconditioning?
must you not be preconditioning?
must he not be preconditioning?
must we not be preconditioning?
must you not be preconditioning?
must they not be preconditioning? 	must I not have preconditioned?
must you not have preconditioned?
must he not have preconditioned?
must we not have preconditioned?
must you not have preconditioned?
must they not have preconditioned? 	must I not have been preconditioning?
must you not have been preconditioning?
must he not have been preconditioning?
must we not have been preconditioning?
must you not have been preconditioning?
must they not have been preconditioning?