Bathilda Bagshot's carcass spoke in Parseltongue while it was occupied by Nagini. Isolt Sayre, a direct descendant of Salazar Slytherin, was able to understand a Horned Serpent which she regularly visited but was not able to speak Parseltongue herself.
What they fail to see is that she is already dead, and she's luring them in to kill them. Bathilda speaks to Harry alone in parseltongue, and although the audience can see the snake appearing from a disappearing body, it does not explain how Nagini could've held Bathilda's corpse long enough, let alone fit inside it.
The ability to actually speak Parseltongue — not just imitate it as Ron Weasley did — was considered an attribute of a Dark wizard, which was partly due to the fact that both Salazar Slytherin and Lord Voldemort possessed this ability. Another notable Dark wizard who was also a Parselmouth was Herpo the Foul.
Bathilda Bagshot met a tragic end. She was murdered through the use of Dark Arts. After her death, her body was animated by Lord Voldemort, who used his snake, Nagini, to inhabit her corpse. This was done as a trap for Harry Potter, who Voldemort reasoned would visit Bathilda's cottage.
Hermione comes out with two cups of tea and a copy of Rita Skeeter's book—she'd found it in Bathilda's house with a note from Skeeter, thanking her and claiming that she said everything the book contains, even if she doesn't remember talking.
It also needed to be recovered "under conditions of need and valour". To fulfil these conditions, Snape deposited the real sword in a frozen lake in the Forest of Dean and used his corporeal Doe Patronus to guide Harry to the sword.
Harry, as heir of Gryffindor, possessed the love of this Muggle-born woman in his very blood and was the perfect champion to stand up against the heir of Slytherin.
After Voldemort is destroyed, Harry presumingly loses his ability to speak Parseltongue. He is relieved and never attempts to speak it again until the events of The Cursed Child.
However, given the context of concealment and fear of danger among the characters in the excerpts, it might be inferred that Bathilda didn't speak in front of Hermione possibly to protect a secret or because she feared some form of retaliation, though these are speculative answers.
Because some snakes can sense heat and movement in a way humans cannot, Nagini was able to detect Harry and Hermione even when they were under the Cloak of Invisibility.
The prevailing theory has been that Voldemort gradually lost his nose (and humanity) throughout his life due to his exclusive use of Dark Magic. The more Dark Magic he tapped into, the less human he became both figuratively and literally. This was only amplified as he split his soul to create the Horcruxes.
Sometime afterwards, Bathilda was murdered through the Dark Arts and her body was animated by Lord Voldemort using his snake, Nagini. He left Nagini there as a trap, thinking that Harry Potter may visit Godric's Hollow to see his parents' grave and their home.
Family. Snape's family background is mostly shown in flashbacks during the course of the last three novels. Snape was born to Eileen Prince, a witch, and Tobias Snape, a Muggle, making him a half-blood (hence the name, "Half-Blood Prince").
The scar is no longer dark, and instead has faded almost to his usual skintone. Scars do fade with time, but J.K Rowling wrote in the book that: "The scar had not pained Harry for nineteen years. All was well." Many people believe the fact the scar has gone dormant after he left Hogwarts is why it faded.
Her real parents were Daneel and Dean Novak, Pureblooded wizards. Turns out Daneel was Tom Riddles younger sister, Daneel Riddle. Of course, the Riddles were related to Salzar Slytherin himself, and this made Hermione the living heir of Slytherin.
Since goblin metal takes in only that which makes it stronger and rejects anything that would weaken it, Gryffindor's blade couldn't have been turned into a Horcrux. Likely, the soul fragment would have been rejected, which could have seriously impacted Voldemort's plans in Harry Potter.
Dorea Black is the connecting force between Harry and Draco, making the rivals distinct cousins. Due to the tragic deaths of Harry's parents and grandparents, the Black family tree shows that Draco is one of Harry's closest living relatives.
Honestly, Hermione knew Dobby was a lost case... nothing could have revived Dobby after the attack or she would have definitely helped Harry with Dobby considering she was the girl who started S.P.E.W(Society for the Elfish welfare) and fought for elf rights. There was nothing to be done at that point.
His dad gave it to him. To elaborate on Icecreamdif's answer, he inherited it as a family heirloom dating back to Hardwin Potter, who married Iolanthe Peverell, granddaughter of the Cloak's original owner Ignotus. It was passed down to the eldest male of each new generation of Potters since then.
After the fall of the ministry, the death eaters would have discovered that Dumbledore intended for the sword to go to harry in his will - so Snape was ordered to hand it over to Bellatrix for protection. Snape gave them a fake and found a way to get the real one to harry.
