butterbeer
Harry Potter and the Sorcerer's Stone is its real name. Although it is only known as this in the US and some other countries. It is called Harry Potter and the Philosopher's Stone in most places, including in the UK.
I never heard the word "patration" in the context of Harry Potter (or otherwise). Check the spelling - perhaps you spelled it wrong.
The killing curse from Harry Potter is the latter. Abra Cadabra is nothing to do with Harry Potter however avada kedavra may have come from that word because it does sound similar. The Harry Potter curse is Avada Kedavra, which is Aramaic and means "I obliterate when i speak". Abracadabra is also Aramaic but means "I create when I speak".
One word. From Harry Potter and the Deathly Hallows, Chapter 24, "The Wandmaker": "'Yes, he asked,' whispered Ollivander. 'He wanted to know everything I could tell him about the wand variously known as the Deathstick, the Wand of Destiny, or the Elder Wand,'" (USA Scholastic hardcover edition, p496).
Accidentally
The second (and third) word Harry Potter said was "nothing".
The fifth word of Harry Potter and the Half-Blood Prince is 'and'.
No, berserk is an English word.
No.
I am not aware of Harry Potter repeating a certain word or phrase regularly.
Harry Potter. The word "homonymous" means "having the same name".
No where.
The first word in 'Harry Potter and the Half-Blood Prince' is 'it'. The next five words are 'was nearing midnight and the...'.
Harry Potter and the Philosopher's (Sorcerer's) Stone by J.K. Rowling has 76,944 words. There are seventeen chapters in the book and 223 pages (UK edition).
The first word is "not".
Nitwit