Similarly to
Snape uses his doe Patronus to show Dumbledore that he never fell out of love with Lily, his childhood best friend. Warner Bros.
A doe. And in his final battle with Lord Voldemort, Harry explained the significance of this to his adversary, and to us: 'Snape's Patronus was a doe,' said Harry, 'the same as my mother's, because he loved her for nearly all of his life, from the time when they were children'.
Severus Snape and the Deathly Hallows
He even sent his Patronus to guide Harry Potter to the sword of Gryffindor (a known Horcrux-killer) in a nearby lake.
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.
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.
Snape's secrecy is revealed to have been a mask and he has sacrificed being well-liked to be able to save Harry, all because of his love for Harry's dead mother: the only friend Snape ever had.
As Rowling explained in a series of tweets, Snape loved Harry's mother, Lily, and his unrequited affection drove him to resent Harry's father, James — and by extension, Harry himself.
So when Ron said three, it wasn't a mistake. He meant there were three more horcruxes to destroy before being able to destroy the fourth and final piece which was in fact Voldemort himself.
Snape was born to Eileen Prince, a witch, and Tobias Snape, a Muggle, making him a half-blood (hence the name, "Half-Blood Prince"). This is rare for a Death Eater, as remarked in the last book, though Voldemort himself also had a Muggle father.
In order to conjure the avada kedavra curse, you have to want to kill your victim. We all know that Voldemort could easily kill a child without an ounce of remorse... but not Snape. Snape didn't want to kill Dumbledore, and this was why the spell was blue instead of the usual green.
For the Potter uninitiated, “always” is how Snape explains to Dumbledore in the final book why his Patronus takes the same shape as the one belonging to his long-lost love: Harry Potter's mother, Lily.
They were close friends, she saw in him someone special that she could care about. But she couldn't be with him. So, it seems like it was very unlikely that Lily ever found out Snape loved her.
One is that Severus Snape is a master of Occlumency and therefore a difficult target for Voldemort to see through. The second is that Harry himself was not able to block Voldemort, and therefore the overall plan between Snape and Dumbledore was too critical to risk its discovery.
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.
The acclaimed author explained that Harry paid tribute to Snape because of “forgiveness and gratitude.” Though Snape bullied Harry, he also saved him. “Harry hoped in his heart that he too would be forgiven.
Snape told him to. It was necessary for Harry to take his tears so that he would know what he needed to do to defeat voldemort. Especially since the only other person that could tell him was Dumbledore and he was dead.
Snape calls Lily a Mudblood, Lily tells James that she would never date him because he's an egotistical jerk. Later, Snape tries to apologize for calling Lily a Mudblood, but she's not interested; she ends their friendship due to his association with Death Eaters.
"The first thing Snape asks Harry is "Potter! What would I get if I added powdered root of asphodel to an infusion of wormwood?" According to Victorian Flower Language, asphodel is a type of lily meaning 'My regrets follow you to the grave' and wormwood means 'absence' and also typically symbolised bitter sorrow.
The simple answer: She didn't love him. The more complicated answer: He proved again and again that he wasn't willing to listen to Lily, respect her or her views, or love her in a healthy way.
Snape tells Harry that he, Snape, is the Half-Blood Prince, and that Harry should not use his own spells on him, as Harry's father did. Harry dares Snape to kill him and calls him a coward once more.
There is no evidence to show that Voldemort ever knew Snape had betrayed him by revealing his plans to Dumbledore; on the contrary, there is a fair amount of circumstantial evidence to indicate that he didn't.
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.