Corrected entry: In the first potions class, Slughorn shows them a few potions and says that these are some of what the students should be able to prepare after completing their N.E.W.Ts. But later on in the book, Ron asks Harry to check his textbook to see if they can prepare a stock of it for themselves. Harry says it's very complicated and that it takes six months to stew. If that were so, how did Slughorn prepare it for their first class? He barely had even 2 months since Dumbledore hired him.
Corrected entry: When Harry and Dumbledore are in the second chamber in the cave it says, "The greenish glow and the light from the two wands." There should be only be one wand lit which is Dumbledore's, because it never says Harry lights his wand, and it is illegal for Harry to use magic outside of Hogwarts because he is not "of age".
Correction: At the top of the same page, it says "...with Harry on his heels, *lighting his own wand* hastily as he went."
Moreover, if Dumbledore has as much power to be able to amend the ability to apparate/disapparate out of Hogwarts, he can surely bend the rule to allow Harry to use magic outside of Hogwarts for that short amount of time as necessary.
Corrected entry: Malfoy used the Imperius curse on Madam Rosmerta to have her deliver the cursed necklace to a Hogwarts student. If Hogsmead is "outside of school" and Malfoy was underaged at the time, shouldn't the Ministry investigate the use of an Unforgivable Curse so close to Hogwarts? And if so, wouldn't they have found out that Rosmerta was cursed?
Correction: The way I understand it, the phrase "outside of school" refers to when students are in the Muggle world during the summer. Since Hogsmeade is an entirely wizarding village, I would think that while the Ministry certainly would investigate the matter, it would be difficult for them to ascertain who specifically performed the curse; there are sixteen groups of underage students (3rd, 4th, 5th, and 6th years, from four Houses) who are allowed to visit the village.
True. but in book 2, the ministry knows what type of magic has been performed in the Dursley's house (by Dobby), as all the underaged have the trace on them. Therefore, the ministry MUST know that an Imperius curse (an unforgivable curse!) has been shot in the village at that moment in book 6. Since performing it on a human being can send you to Azkaban for life, the ministry should have investigated the matter thoroughly AND informed the headmaster of Hogwarts. When Draco is explaining things, it seems as if Dumbledore would never have guessed someone in the village was under the Imperius curse.
According to the wiki the trace is lifted whilst the students are attending Hogwarts. They can use magic freely then, this include the Hogwarts express at least so it's not unlikely Hogsmead counts as well. It is put back again during holidays, but not weekends. It is also true that muggle born children like Hermione and Harry are more closely monitored than one with a wizard family like Draco, since magic happens around him a lot more often. Next to that, if they do notice him using magic they might investigate but then find out he is the son of Lucius Malfoy and drop the case anyway because they fear him.
Corrected entry: It states in the Half-Blood Prince that the ministry can only detect magic, not its perpetrator. Therefore, when Dumbledore visits Harry at the beginning of the book and performs magic, shouldn't the ministry have detected it, knowing that Harry was an underage wizard? (There should have been no magic being performed at the house at all).
Corrected entry: In the US version, page 485, Slughorn tells Harry that he has "a house-elf taste every bottle after what happened to your poor friend Rupert". Slughorn should have said "poor friend Ron", not Rupert. One assumes this is a reference to Rupert Grint, who plays the character Ron in the movies.
Correction: If you notice, Slughorn calls Ron a different name earlier in the book as well, so this is not J. K. Rowling's mistake, but a character mistake, highlighting Slughorn's lack of care for Ron. But the assumption (that it is a reference to Rupert Grint) is plausible.
Corrected entry: In the American edition, page 188, Slughorn says, "One tiny bottle of felix felicis is enough for twelve hours' luck. From dusk til' dawn, you will be lucky in everything you attempt." But then on page 476, Harry says, "I don't reckon I'll need all of it, not twenty-four hours' worth."
Corrected entry: In the part of the book where Harry holds Quidditch trials the book says that there are first years holding the old school brooms, but in the first book it says that first years are not allowed to have brooms or be on the house Quidditch teams.
Correction: Since Harry was allowed to join the House Team in his first year, it is logical to assume that the rules have now been changed. As to the first years having brooms, they are not their personal brooms (which they are not allowed to have) but the house brooms.
Corrected entry: It is repeatedly said through the books that no one can apparate or disapparate on Hogwarts' grounds. However, both Dobby and Kreacher apparate to Harry when he calls them. [It has been argued that house-elves have magical powers of their own that aren't affected by wizard law. So it's not entirely unplausible that Dobby and Kreacher can Apparate around the castle, even with the anti-Apparation charm in effect.]
Correction: Jk Rowling has said that Dobby and Kreacher, being house elves, can. It's not apparating or disapparating, it's their own kind of house elf magic.
Corrected entry: In this book, during the end, Snape says that he is the Half-Blood Prince. Earlier, when Harry is at the Weasley's for Christmas, he wonders if his dad was the Prince. He looks in the book, and it says that the book was from fifty years ago. He is depressed by the fact that his dad wasn't at Hogwarts fifty years ago. In the fifth book, when Harry is in Snape's pensieve, he sees his dad and Snape finish their O.W.L.s. This would mean that they were in the same year at Hogwarts.
Correction: When Harry first wonders about if the book belonged to James Potter, it is under the assumption that the Prince had owned the book when it was new. But as we later find out, poor students (such as Snape) can get cheap, used books through a special fund at Hogwart's. It is therefore quite possible that Snape had a ten-year old copy of the book at the time when he dubbed himself the Half-Blood Prince.
The book could have belonged to Snape's mother, Eileen Prince. Snape could have borrowed her books.
Corrected entry: On page 425 of the US version, it says '"Nice commentary last match." said Ron to Luna as she took back the green onion, the toadstool, and the cat litter.' But a couple of paragraphs later it says '"What is this, by the way?", he added, holding the onionlike object up to eye level.' Didn't she already take back everything a few lines ago?
Correction: Even though Ron gave the Gurdyroot back doesn't mean he couldn't have picked it up again to ask what it was. Everything was still outside of Luna's purse, so it's very possible Ron could have just been curious and grabed it before he asked Luna about it.
Corrected entry: In chapter 23, "Horcruxes", at the end of Slughorn's memory Slughorn told Riddle not to mention to anybody that they have talked about horcruxes because Dumbledore is very strict on that point. But at the time the headmaster wasn't Dumbledore, when Riddle was a student the headmaster was Dippet.
Correction: Slughorn mentioned nothing of Dumbledore being headmaster. He was talking about Dumbledore because he was one of the more prominent teachers that have great influence on the goings-on of the school. Much Like McGonagall is in the present staff. She's much more important than, say, Flitwick or Sprout.
Corrected entry: In the chapter "Horace Slughorn", in the house Harry sees 'something darkly red and gluttonous,' which is later described as dragon's blood. However in the fifth book, the chapter "Hagrid's Tale", Hagrid uses dragon meat on his wounds, but it says that the meat oozed 'greenish blood'.
Correction: There's nothing in the series to suggest all dragons have similar blood. The blood of a Welsh Green might very well be green, while the blood of a Noregian Ridgeback is red, or blue, or black. We just don't know either way.
Correction: Slughorn was the potion teacher at hogwarts for some years before he retired. That doesn't mean he will stop making potions. There is no reason why he can't have a supply.