Differences between books and show

Spencer:
Spencer is a very intelligent girl in both the books and the tv show but in the books as A starts stalking the girls she starts doing stupid things, she cheats on a paper and says she wrote it, but it was Melissa who did. While she was at a summer camp in an university she starts taking drugs and buying them from a guy named Phineas who turns out to be part of the A team. She also, accidentally gives pot brownies at a party at Princeton University while non of this happens in the books

Hanna:
In the show, Ali tells Hanna to puke her food, but in the books, she has bullimia. It all started when she visited her dad and brought Ali along. She met Kate her new step sister and when Kate and Ali bonded she felt ugly and miserable and went to the bathroom and made herself puke. In the books she is also in a relationship with Mike, Aria's brother while in the tv show it was a one time thing.

Aria:
In the show Aria and Ezra have a long going relationship, while in the books they broke up really soon and she dated a couple of guys until she started dating Noel Kahn, which she hates in the tv show. They have a pretty stable relationship until Klaudia comes along and things start going downhill. Then when they are finally getting back on track A attacks Noel and he is sent to a hospital to recover from his near death experience.

Emily:
In the show Emily is in love with Maya, the girl who moved in in Ali's old house. They begin a relationship together but she has to go to a rehab like camp for a while, when she comes back they get back together but their relationship ends in traged when she is killed by Nate, her stalker, which tricks Emily into thinking he is Maya's cousin. In the novels while taking a break with Maya she meets Trista and hooks up with her. Later on causing Maya and Emily to break up. She then meets a boy named Isaac and they start dating making Emily a bisexual person, they have sex and she gets pregnant and later on puts the baby up for adoption.

Mona:
In the show Mona was friends with Hanna but was secretly part of the A team and she tries to recruit Spencer and get her to help torment the girls which Spencer denies, this is all correct but in the books when she tries to kill Spencer, because she didn't join the A team. Mona falls over the edge and dies.

Jenna:
In the show Jenna is portrayed as evil and mean and is always after the girls butin the books she is the exact opposite.Toby would rape her when they were younger so she asked Courtney (fake Ali) to throw the firework at the tree house causing her to be blind. Toby was blaimed for what happened and sent of to military camp. She was one of the only people who knew that there were two sisters, Alison and Courtney since she had met them both. This secret cost her her life, when Alison came back and killed her justas she das killed Ian.

Toby:
In the show, Jenna would make Toby have sex with her, but in the books it was the contrary, he would rape Jenna all the time and she was too scared of him to say anything. WHen Alison accidentally blinded Jenna she blackmailed Toby into taking the blame, if he didn't she would tell everyone what he had done to Jenna. He is sent of to military and comes back a changed man. He meets Emily and they become friends, Emily then starts thinking he is A and told him something like this: "i know everything, get away from or i'll call the police" she was referring that she thought he was A but Toby thought she was talking about what he had done to Jenna, so he left Emily alone and went into the woods, were he commited suicide. He wrote a note to Jenna explaining how sorry he was and one to Emily.

Ian:
In the show Ian hooked up with Spencer and Ali while he was dating Melissa for the first time, but in the show they portray him as a man with anger issues who tries to kill Spencer. In the books he and Spencer never like each other after he started dating Melissa after Ali's disappearance. Spencer thought he was A so she was glad when he was held responsible for Ali's death and sent to prison, but while he's away she realizes he's not the killer. Ian starts putting all the pieces together about the twins so the real Alison kills him.