How was Severus Snape still on Albus Dumbledore's side?

Was Severus Snape still a member of the Order of Phoenix after he killed Albus Dumbledore did they still trust him after what Harry Potter told them what he saw?

When Severus Snape killed Albus Dumbledore, everybody believed that he did it because he was on Lord Voldemort's side so no, he was no longer a member of the Order of the Phoenix. However, after Harry Potter witnessed Snape's memories and learned that he was indeed on their side, they believed him. By this point Snape was dead and the Order of the Phoenix had been disbanded for the final time.

Did Severus Snape fire Argus Filch?

No he didn't. Filch was still there.

How did Severus Snape invent spells?

he used dark magic help from voldemort when he was still in hogwarts

Is Albus Severus Potter in Gryffindor?

Severus Snape is Hogwarts' Potions master. He had become Dumbledore's staunch supporter after being a Death Eater, but he had to kill Dumbledore to convince Lord Voldemort that Snape was still on the dark side. Then, under Voldemort's direction, Snape became Defense Against the Dark Arts master then Headmaster. He loved Lily Evans, but Lily married James Potter. Snape had saved Harry's life twice (from Remus Lupin under a full moon (in the film only) and by sending the Order to the Department of Mysteries "to save Sirius"), but he still hates Harry, because Harry is James' son.

What did Severus Snape reveal about Harry Potter's mother?

Snape's mother was called Elieen Prince and she was a pure-blood witch. His father was a muggle making Severus a half-blood. He used his mother's maiden name and his blood status to form he nickname.

Is Albus Dumbledore alive in Harry Potter and the Deathly Hallows?

Albus Dumbledore is dead. He was killed by Severus Snape in Harry Potter and the Half-Blood Prince. The two agreed that Snape would kill Dumbledore, instead of Malfoy doing it because Dumbledore was going to die anyway.

Did Severus Snape die trying to save Harry Potter?

Yes, Severus Snape died in Dethly Hallows. Voldemort realized that he wasn't the true owner of the Elder Wand because Snape killed its previous owner (Albus Percival Wulfrock Brian Dumbledore). Therefore, Voldemort had Nagini bite Snape on the neck, killing him.Source: http://www.sparknotes.com/lit/potter7 and my own knowledge of the books

Which Hogwarts professor used to be a Death Eater?

Severus Snape. Also, the fake Alastor Moody was still a death eater.

Is Severus Snape still the head of Slytherin house?

It's hard to tell, since we don't actually see him as headmaster and only hear bits of information. Given that the school was under death eater rule, Snape did his best to protect the students as much as he could. Unfortunately, he couldn't stop the Carrow's from torturing students otherwise Voldemort would have questioned his loyalty.

Why did Albus Dumbledore want Lord Voldemort to know when Harry Potter was to be moved?

He didn't want to because that would be more complicated, but he had to. Severus Snape joined the Death Eaters straight out of school. After Lily Evans' life was put in danger he convinced Voldemort he was joining the Order of the Phoenix as a spy for them. In reality, he was spying on the Death Eaters for the Order and only passing on select information to Voldemort. As time went on this information had to get better because Snape became more trusted. Dumbledore let Snape tell Voldemort when Harry was going to be moved to ensure Voldemort still trusted Snape.

What happens with Severus Snape?

The following is a spoiler; I suggest you read the books, or wait for the movies.At the end of book 7, Severus Snape is betrayed by Lord Voldemort, who at that time still believes that Snape works for him. He has Nagini kill him. Snape, deadly wounded, passes some memories to Harry, right before his death. Harry Potter looks at them in the Pensive and learns that Snape was loyal to Dumbledore, and that the killing of Dumbledore was suggested by Dumbledore himself, for two reasons: 1) Dumbledore didn't have much time to live anyway; 2) it was convenient, for the planes of the Order of the Phoenix, for Voldemort to completely trust Snape.The following is a spoiler; I suggest you read the books, or wait for the movies.At the end of book 7, Severus Snape is betrayed by Lord Voldemort, who at that time still believes that Snape works for him. He has Nagini kill him. Snape, deadly wounded, passes some memories to Harry, right before his death. Harry Potter looks at them in the Pensive and learns that Snape was loyal to Dumbledore, and that the killing of Dumbledore was suggested by Dumbledore himself, for two reasons: 1) Dumbledore didn't have much time to live anyway; 2) it was convenient, for the planes of the Order of the Phoenix, for Voldemort to completely trust Snape.The following is a spoiler; I suggest you read the books, or wait for the movies.At the end of book 7, Severus Snape is betrayed by Lord Voldemort, who at that time still believes that Snape works for him. He has Nagini kill him. Snape, deadly wounded, passes some memories to Harry, right before his death. Harry Potter looks at them in the Pensive and learns that Snape was loyal to Dumbledore, and that the killing of Dumbledore was suggested by Dumbledore himself, for two reasons: 1) Dumbledore didn't have much time to live anyway; 2) it was convenient, for the planes of the Order of the Phoenix, for Voldemort to completely trust Snape.The following is a spoiler; I suggest you read the books, or wait for the movies.At the end of book 7, Severus Snape is betrayed by Lord Voldemort, who at that time still believes that Snape works for him. He has Nagini kill him. Snape, deadly wounded, passes some memories to Harry, right before his death. Harry Potter looks at them in the Pensive and learns that Snape was loyal to Dumbledore, and that the killing of Dumbledore was suggested by Dumbledore himself, for two reasons: 1) Dumbledore didn't have much time to live anyway; 2) it was convenient, for the planes of the Order of the Phoenix, for Voldemort to completely trust Snape.

What does harry find out about snape when Hermione set fire to snape robes?

Nothing, he still thinks Snape is the culprit.