For the most part, The Harry Potter films stick closely to the books minus some minor storylines that may not have benefited the main plot of the battle between Harry (Daniel Radcliffe) and Voldemort (Ralph Fiennes). As for the characters, many fans have noted there's a fundamental difference between the book Harry and the movie Harry, and the same could be said about Hermione (Emma Watson) and Ron (Rupert Grint). But with all those differences, there haven't been that many... except the fate of one villain. Barry Crouch Jr. (David Tennant) was supposed to die at the end of Harry Potter and the Goblet of Fire.
Source：https://www.cbr.com/harry-potter-movies-barty-crouch-david-tennant-villain/
