Yes, he has been on Albus Dumbledore's side since 1980 when a threat was made on the life of Lily (Evans) Potter.
Harry Potter and the Deathly Hallows Part 2.
Yes
Yes. Alan Rickman reprised his role of Severus Snape in both part of Harry Potter and the Deathly Hallows.
Albus severus and Lily
Severus Snape
Yes
Harry Potter and the Deathly Hallows Part 2 . Albus Severus Potter . ^
Severus Snape was headmaster in book seven: Harry Potter and the Deathly Hallows.
James Sirius Potter, Albus Severus Potter and Lily Luna Potter.
James Potter is the oldest, Albus Severus Potter is the middle child and Lily Potter is the youngest.
Severus Snape put the sword at the bottom of a lake and then led Harry to it.
Severus Snape is the headmaster of Hogwarts in Harry Potter and the Deathly Hallows.