Question: Is it true that J.K. Rowling originally intended for Hermione to have a muggle sister?
Question: Has it ever been explained what happens to a wizard/witch if they don't repay a life debt? Harry should owe one to Snape after Snape rescues him from Quirrell's curse during the Quidditch game, but he never does throughout the series.
Answer: It does not appear that life debts automatically form whenever somebody saves somebody else - J K Rowling has, for example, stated that Ginny did not incur a life debt to Harry when he saved her in the Chamber of Secrets, although she said nothing about what circumstances need to occur for a debt to exist. In Snape's case, there would seem to be several possibilities. 1) A life debt simply didn't form. 2) Snape is protecting Harry because of his love for Lily and his failure to save her, so he may actually be paying off a debt of sorts himself by doing so. 3) Harry's father James saved Snape from almost certain death when Sirius tried to trick him into going into the Shrieking Shack when Remus Lupin was in his wolf form. As such, Sirius may have owed James a debt, which he paid off by saving Harry. 4) A life debt did form but, as Snape died before Harry could pay it off and, insofar as we know, had no relatives that the debt could pass to, Harry was let off the hook.
Question: After the incident at the zoo, on Dudley's birthday, Harry is restricted to his cupboard until after the summer holidays start (see beginning of Chapter Three). If Dudley's birthday is before the holidays, then why does Mrs. Figg normally watch Harry that day (except this year)? Any year when Dudley's birthday was not on a weekend, Harry could have simply gone to school as usual.
Answer: Harry has already experienced a few magical incidents, as children from Muggle families usually do. For example, changing a teacher's wig hair to a blue color. If Dudley's birthday is on a school day, his parents probably don't want the risk of a problem at school. It's easier to make Harry stay with Mrs. Figg all day.
Answer: As I recall, Mrs. Figg had broken her leg so she was unable to watch Harry. The Dursleys were then forced to take Harry to the zoo for Dudley's birthday.
That is not the question. The question is why she has been watching Harry every other year, except for this time (due to her injury). If Dudley's birthday happens before the summer holidays begin, why has she been watching Harry during the years when Dudley's birthday is a school day? Harry could have just gone to school.
Thank you for clarifying as your original question was rather confusing. I was assuming that Dudley's birthdays were not celebrated on an actual school day, but later on the weekends and that is why Mrs. Figg watched Harry. I don't think Dudley would be staying home from school every year on his B-Day.
Question: This question is for all the novels. How are all the schools in the wizarding world kept hidden from the muggle world? Surely if a plane were to fly over Hogwarts, people would be shocked at seeing people flying around on broomsticks and using magic.
Answer: International Statute of Wizarding Secrecy is in charge of hiding the general wizarding community from the Muggle world. As for many of the wizarding schools such as Hogwarts, their use of multiple Concealment Charms provide the necessary protection to creatively conceal them from Muggle view.
Also, Muggles usually don't "want" to see magic. Most of them are too convinced that magic is not real. A Muggle might see the occasional wizard/witch fly high above them on a broom, and assume they imagined it.
Answer: There are special spells at work to hide the schools and other places from muggles. In Deathly Hallows for example you can see Hermione cast a few when they are in the woods. An example is "Repello Muggletum", which is a barrier that causes Muggles who hit it to forget they were there and turn around.
Question: I heard that Quirrell was the muggle studies teacher before this year. So after he took defense against the dark arts, why not give muggle studies to Arthur Weasley?
Question: The night when Harry is given to the Dursleys takes place in 1981. McGonagall and Dumbledore each say something about "for eleven years", so they are referring to the year 1970. What happened that year? I know from the sixth book that Voldemort had been around and gathering followers since way before then; he had some followers when he was 28 and he visited Hogwarts to apply for teaching Defense Against the Dark Arts.
Question: Why did Snape have Filch treat his wounds from the three-headed dog? Why not go to Madam Pomfrey in the hospital wing, considering that Snape wasn't really doing anything wrong after all?
Answer: I think Snape wanted to keep what happened quiet while he investigated Professor Quirrell, and Madam Pomfrey was more likely to inform Professor Dumbledore. Filch, who would consider Snape something of a kindred spirit, would not feel a need to report it to anyone, particularly if Snape asked him to say nothing about it.
Question: Do magical folk generally live longer than Muggles? Considering that Minerva is described as having black hair, even though she is old enough to have taught Harry's parents, and Dumbledore is more than one hundred years old (according to the Harry Potter Wiki).
Question: Does Harry say Percy's name ever in this book? If not, is this the only book he does this in?
Chosen answer: No, he doesn't. He says Percy's name in the second book "Harry Potter and the Chamber of Secrets", when they are on the train ride home.
Question: Has JK Rowling said what happened to James Potter's parents and Lily's? They were only 21 when Voldemort killed them, and most people of that age still have living parents.
Answer: James had older parents who died of some type of wizarding ailment. It's suspected to be Dragon Pox as that can be fatal to elderly wizards. All that is known of Lily's parents is they died of a normal muggle death. As to what "normal" means though and the age of her parents, that has never been said.
Question: Why did Professor Quirrell really have the garlic in his classroom? I know that some people thought he was afraid of a vampire who wanted revenge. Since he was serving Voldemort, however, it seems that a vampire would not be a serious concern for him.
Answer: At that point, Voldemort had little to no power and was reliant on Quirrell to protect him, not the other way around. No one knew Voldemort still existed, and Quirrell wanted to ensure his safety until he was restored to corporeal form. He may have believed garlic would be an added protection but more likely it was just for show and to create a sense of drama to enhance his phony persona.
This is purely speculation but could it also be considered that the garlic and story about having had an argument with a vampire are all a ruse to cover his quirky behaviour following his meeting with Voldemort? As in, people started the rumour, so he plays on it to make it more believable and give him a better cover story?
Question: What did Harry and his friends come across when they were trying to escape from Filch?
Answer: Presumably you are referring to when the trio come upon "Fluffy," the three-headed dog, that is kept in the restricted area of the castle. Inside the room there is a magical self-playing harp that keeps "Fluffy" asleep when it's playing. Hermione also noticed Fluffy was lying atop a floor hatch, which leads to where the Philosopher's Stone is hidden.
Answer: In addition to raywest I will add that at this point in the book, the Harp isn't playing and Fluffy is awake. It is also not known at this point that music puts Fluffy to sleep.
True, although the question only relates to what the trio came across while evading Filch, not about knowing what any particular object is or does. (I just added an explanation as an aside.) However, I'm not sure now the harp had been installed yet when they first found Fluffy, so it was probably about the floor hatch.
Answer: Yes. J.K. Rowling was going to give Hermione a younger sister who was a muggle. However, by the time "Harry Potter and the Order of the Phoenix" came out, she felt that it was too late.