One theory (and the most sensefull) suggest that Snape thought,if Neville is the chosen one(prophecy is about both harry and Neville) then Lilly will not have to sacrifice herself.
He was cruel to many students, but especially toward Neville Longbottom. It was no fault of Neville's but was instead because of Snape's love for Lily. Neville was almost the Chosen One, and the fact that he wasn't broke Snape's heart to look at him, which caused Snape to lash out cruelly at an innocent child.
Neville Professor Snape Neville fears Professor Snape who treats him rudely with sarcastic comments. Neville seems afraid of this harsh treatment that makes him feel inferior constantly.
If Voldemort had made the Chosen One Neville, then he would not have survived Voldemort's murder attempt on him as a child. Snape would not have asked for him to protect anyone as he did not care for the Longbottoms, this may have meant he never became a double agent too.
Why did Snape hate Hermione? I think Snape was probably initially impressed with Hermione, but later frustrated with her, for a few reasons. Hermione was very book-smart and could come up with answers quickly, but didn't seem to be very good at improvising or trying to improve on existing Magic.
The Real Reason Snape HATED Neville So Much | Harry Potter Explained/Theory | Premium Theory
Who did Harry hate more, Snape or Umbridge?
Umbridge earns far more hate than Snape. While Gryffindors have to deal with Snape's biased behavior during potions class, Umbridge creates rules that affect all school life. Her educational decrees are constantly banning one thing or another.
For example, Lily Evans told her former friend Severus Snape that if he was going to refer to other Muggle-borns as "Mudbloods", then he had to use the term for her as well, not minding it much when he did so. Hermione Granger declared that she was proud to be a "Mudblood" in 1998.
Cuz the prophecy was not just based on date of birth, there were other conditions too which both Harry and Neville fulfilled but except that Voldy marked Harry as his equal by giving him the scar rather than Neville and so Harry became the chosen one. "The one with the power to vanquish the Dark Lord approaches...
What would have happened if Voldemort chose Neville?
It was answered very eloquently by commenter Sooooo, who explained that we'd have a dead Neville on our hands: The key part of what saved Harry from Voldemort was Lily being given a choice by Voldemort (at Snape's request) to stand aside. Alice Longbottom would not have been afforded the same opportunity.
Voldemort intended Draco to die in the attempt to kill Dumbledore so that Lucius would be punished for his failure to retrieve the prophecy from the Ministry of Magic.
To defend her students, McGonagall casts a series of spells Snape's way, but he manages to evade all of them before flying away. But what McGonagall doesn't know is that Snape is actually a double agent working for Dumbledore, so he has no intention of harming her. That being said, Snape holds back quite a bit.
The flames became a ring of fire that filled the corridor and flew like a lasso at Snape. Snape then turned the descending flames into a great black snake that McGonagall blasted to smoke and turned into a swarm of daggers, which she directed towards him.
As the series progresses, it is revealed that his treatment of Harry stems from Snape's bitter rivalry with James when they were in school together. In particular, James and Sirius bullied Snape, which according to Alan Rickman caused the already lonely boy to further "shut himself in".
He simply didn't value the Gryffindor traits as much as he valued others. We really don't see much of an average day's activity at Hogwarts, so it is hard to say. Maybe Snape gets on just fine with quiet Gryffindors. We would need to see how Snape interacts with Ravenclaws and Hufflepuffs as well for comparison.
In Harry Potter and the Deathly Hallows Part 2, Neville is actually the person who destroys Voldemort's last Horcrux in Nagini, rendering him mortal, meaning that he and Harry truly delivered the final blows to Voldemort.
Severus suffered terrible remorse when Voldemort decided that Harry Potter was the subject of the prophecy and that Lily Evans, the woman whom he always loved, was now in danger as a result of his actions. He begged Voldemort to spare her, who agreed.
What is the significance of Neville killing Nagini?
The killing of Nagini was very representative of the houses Gryffindor and Slytherin. The sword was originally Godric Gryffindor's, and Nagini was a snake, Salazar Slytherin's symbol, who was owned by a descendent of the Slytherin Family Line.
Notably, Voldemort appeared to be entirely unaware of this split, as he later created a seventh Horcrux in his quest to have six, and continued to target Harry Potter despite him now holding part of Voldemort's own soul.
What makes Harry explicitly the chosen one in the books is 3 things, 1) Voldemort chose him that night to be the chosen one and decided to kill him and his family personally to avoid the prophecy, 2) Harry and Neville actually talked this out and Harry chose to take the possible responsibility off of Neville and to be ...
After Voldemort's defeat by Harry at the Battle of Hogwarts and the restoration of the Ministry of Magic by the new Minister, Kingsley Shacklebolt, Umbridge was sentenced to life imprisonment in Azkaban for her crimes against Muggle-borns.
He took particular pleasure in taunting Hermione Granger, who just happened to have Muggle parents. Malfoy called her 'Mudblood', a very grave insult referring to a wizard or witch born to non-magic parents.
Lily called Severus “Snivellus “ because only a Snivellus would call his best friend a filthy little mudblood. Severus became Snivellus when he was a bigoted bully, attacking a friend whom actually stopped his enemies from bullying him.
In Harry Potter and the Deathly Hallows: Part 1, Bellatrix used her knife to carve the word "mudblood" into Hermione Granger's arm. The film version of the knife bears a resemblance to cross-shaped spearheads that leave a hard-to-heal wound.
