The pair were parted when the Sorting Hat placed Severus in
Rowling said the sorting hat made only 7 mistakes, one of them was placing Snape into Slytherin.
Snape had a strong personal preference for Slytherin when he entered Hogwarts, which the Sorting Hat would have taken into consideration. Snape's personality conforms to the Slytherin values of ambition and cunning.
Snape was always a Slytherin, and that never changed. Even his bravery is not the the Gryffindor kind, and Snape also prefers Slytherin, and he definitely isn't chivalrous, so he would never be a Gryffindor.
In the case of Snape. he was Sorted into Slytherin because he was ambitious, leaning towards the Dark Arts, his mother was one, AND he had an anti-Muggle bias, same as Salazar Slytherin himself.
But when they went to Hogwarts, everything changed. The pair were parted when the Sorting Hat placed Severus in Slytherin and Lily in Gryffindor, and while Lily thrived in her new, magical life, Snape was essentially placed in close quarters with the likes of Lucius Malfoy, Avery and Mulciber.
And this is why Hermione does not fit into Ravenclaw, since she lacks their creativity of thought. When you also add in her fearlessness and her strong convictions about right and wrong, which are inherently Gryffindor traits, then there was even less of a chance she'd end up wearing blue and bronze.
Snape uses his doe Patronus to show Dumbledore that he never fell out of love with Lily, his childhood best friend. Warner Bros.
Harry would have been internally conflicted if he had been Sorted into Slytherin. Although he still would have felt that Hogwarts was the only place he had ever belonged, he might have felt wary forming relationships with the children of Death Eaters.
Horace Slughorn (1997 - present) Horace, after being convinced by Dumbledore and Harry Potter, returned to Hogwarts as the Potions master. After Severus killed Dumbledore and became headmaster of Hogwarts, it was decided that Horace was to become the Head of Slytherin House once again.
One of the main reasons Dumbledore belongs in Gryffindor and not Slytherin is because he is willing to sacrifice himself for others. Dumbledore fatally injured himself hunting down Horcruxes and even this did not deter him from his fight against Voldemort.
He is cunning
Slytherins are a cunning lot, and there are all kinds of examples of Albus Potter using his wiles to come up with schemes and plans worthy of any member of Salazar's house throughout Harry Potter and the Cursed Child.
He actually asked the Sorting Hat to place him in Hufflepuff, as he was intimidated by Gryffindor's reputation for bravery, but the Sorting Hat didn't agree. They debated it for so long, that he was close to being what is known as a Hatstall, which is a term for any student whose Sorting takes longer than five minutes.
This, of course, hints at one of the most major twists in the entire series: the reveal in the final installment that Snape has been on Harry's side the entire time because of his love for Harry's mother, Lily, who was killed by Lord Voldemort.
He's also notoriously anti-Harry; even though he doesn't appear to be trying to thwart Harry directly over the course of the previous six books, he certainly dislikes the boy. After killing Dumbledore at the end of Book 6, Snape has us convinced that he's on Voldemort's side for sure.
Here's the thing: Dumbledore knew that Snape was mean to the students, but the headmaster still allowed it. It's likely that he did this because he believed that his students needed life lessons, including how to deal with mean teachers.
1 Albatross
As the rarest Patronus in the Wizarding World possible, the Albatross represents an enormous bird that flies freely across any sea. This rare Patronus represents those who are simultaneously fearless, optimistic, happy-go-lucky, and ambitious.
With Harry and Hermione despondent after the events in Godric's Hollow and Ron trying desperately to find his way back to them, it was Snape's Patronus – the Silver Doe that was somehow familiar to Harry, perhaps because it recalled his mother's own Patronus – that brought them back together.
Ron Weasley
Being Harry Potter's best friend certainly needed heaps of bravery – hence the Sorting Hat not messing around in sorting Ron into Gryffindor, the house of his parents, brothers and sister. But the Hat specifically states that Gryffindors usually have 'daring, nerve and chivalry'.
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.
If Draco had been a Gryffindor, he still would have had parents strongly affiliated with Lord Voldemort and Bellatrix Lestrange as an aunt. Malfoy Manor would've still been a good base for Voldemort. Dumbledore would remain a major threat and Malfoy would have been in a good position to get close to him at school.
At Hogwarts, she, along with her sisters, was sorted into Slytherin. It is suggested in the novels that, as a student, Bellatrix associated with a group of students – including Rodolphus Lestrange, Severus Snape, Avery, Evan Rosier and Wilkes – who nearly all became Death Eaters.
Sirius's early life proved unhappy; he had come to hate most of his relatives, in particular his mother. He rejected his family's pure-blood elitism and reverence for the Dark Arts. At Hogwarts, rather than be sorted into Slytherin like the rest of his family, Sirius was placed in Gryffindor.
Lily Only Ever Saw Him as a Friend
As much as people romanticize Snape's infatuation with Lily, the fact that she did not love him back—at least in a romantic fashion—seems to go ignored by many fans of the series.