The Perks of Being a Wallflower by Stephen Chbosky
In The Perks of Being a Wallflower, Charlie struggles with starting high school and dealing with mental illnesses all while trying to make friends. After Charlie loses his best friend Michael to suicide, he eventually finds a friends in Patrick and Sam. Charlie learns a lot in this coming of age novel.
http://cdn.playbuzz.com/cdn/1a808164-a715-4de5-8822-0d9417b54960/c86ba820-3833-4283-8395-4a3a46250bee.jpg
The movie didn't accurately portray Sam and Patrick as being siblings. In the movie, they danced at homecoming together, which would lead the viewer to believe they were dating rather than siblings. In the novel, Charlie learns the two are related while eating at the big boy when he asks them, "How long have you been 'going out'?" (Chbosky 54). The two respond with laughter and tell Charlie they're related. This specific moment is left out of the movie and seemingly makes things less effective.
https://redapplesite.files.wordpress.com/2016/02/candace-the-perks-of-being-a-wallflower-38360683-640-360.jpg?w=663
In the movie, Ponytail Derek is not as included as he was in the novel. In the novel, he's more of a major character. In the movie, he disappears after a scene or two. In the novel he disappears after Candace gets pregnant, which is also left out of the movie for obvious reasons. In the movie, he slaps Candace across the face and doesn't show up anywhere else in the film. Candace tells Charlie "not to tell mom and dad" about what he just saw and that "she was okay". Ponytail Derek did give Candace the mixtape at the beginning of the movie, which she gave to Charlie.
http://images6.fanpop.com/image/photos/38300000/Mr-Anderson-the-perks-of-being-a-wallflower-38360679-640-360.jpg
Mr. Anderson, as Ben is referred to in the movie, isn't as important of a character as he was in the novel. He wasn't married and he was more of a fatherly, friendly figure to Charlie. In the movie, he was rude in some ways and wasn't as involved with Charlie's life as he was in the book. In the film, the only time we really see the two interacting is when Charlie asks Mr. Anderson "why do nice people choose the wrong people to date"? Mr. Anderson's reply is rather short and isn't as caring as the Mr. Anderson that is portrayed in the novel. Overall, Ben doesn't care as much about Charlie in the film as he does in the book.
http://theinvisibledoors.weebly.com/uploads/2/6/8/0/26809364/9963652_orig.jpg
The novel's entire format is multiple letters from Charlie to a friend. In the movie, Charlie writes very few letters and it messes up the movie's transitions. In the novel, each "chapter" (letter) begins with "Dear Friend," and concludes with "Love Always, Charlie" (Chbosky). Charlie is given a typewriter by Sam for Christmas which he uses to write one letter. The format of writing letters starts out pretty strong in the film and then abruptly stops.