Continuity mistake: After King Louis stabs d'Artagnan with the dagger, the good brother (Phillipe), rushes him and Louis drops the dagger to the prison floor. However, in the next scene, a close-up of the two brothers fighting, Louis has the dagger in his hand again.
Factual error: Six years in a mask and Philippe's teeth are in perfect condition. All that time without brushing or flossing, you'd think he'd have lost some teeth or been in wracking pain from toothaches.
Answer: There would be both genetic similarities and individual differences, and their vocabularies would have developed differently by education and experience. However, Phillipe was heavily tutored before the switch took place, and as "king" he would be able to distance himself (physically, mentally, and emotionally) as much as needed from members of his court until he perfected his role, along with the continued help from those in on the deception. Also, the audience and readers of the novel are expected to employ a certain "suspension of disbelief" in order to allow the story to be told.
raywest ★