External conflict in Harry Potter and the Deathly Hallows?

Answer 1

The external conflict was between Harry and The Death Eaters and Voldemort. The internal conflict was between Harry and Voldemort (voldemort got in Harry's mind {the dreams and visions} and also just the thought because Harry wanted to kill Voldemort.)

Answer 2

The primary one is the horcrux - this is a man vs. nature conflict because it is against nature to split a soul. There are terrible consequences for those who produce and use horcruxes - physical disfiguration, like how we saw Voldemort in the Goblet of Fire, before and after the potion in the graveyard.

Another man vs. nature conflict is the story of the Deathly Hallows, and the 3 brothers who originally had them. 2 of them tried to cheat Death, and paid with their lives for it, while the 3rd brother, the humblest of all, hid from Death with his invisibility cloak, and when his time had come to move on, he removed his cloak, handing it to his son, and "greeted Death like an old friend", as Hermione narrated when reading the story in the Lovegood residence.