Troian Bellisario portrays Spencer Hastings. Spencer is an extreme perfectionist who likes to please her wealthy family, and her friends. She is very competitive, and an overachiever. Spencer is strong willed, smart and kind towards everyone around her, but isn't afraid to take down anyone who is a threat to anyone she cares about. Spencer was a brief member of the "A" team in the final two episodes of the third season tired of being the victim. She is in a relationship with Toby Cavanaugh, who is now part of the Rosewood Police.
Ashley Benson portrays Hanna Marin. Hanna used to have an eating problem. She was overweight, with the nickname 'Hefty Hanna', and after Alison Dilaurentis disappeared, Hanna lost her weight and changed her style, which seemed similar to Ali's, with the help of Mona Vanderwaal her new best friend. Over the course of the series, Hanna cares more about the people around her and tries to protect herself and her friends. She has had few love affairs through the series, currently she is in a relationship with Caleb Rivers (Tyler Blackburn).
Lucy Hale portrays Aria Montgomery. Aria is the artsy chameleon who is an old soul stuck in high school. She is very intelligent, caring, and has a good sense of style. Shes the one who keeps her family together. Aria used too be a tomboy. She would wear black, punk-like clothing and she had pink highlights in her hair. After Ali's disappearance, Aria and her family moved to Iceland and now they're back in Rosewood after there for a year. When Aria and her family came back from Rosewood, she was no longer that tomboy she used to be, she was a girly-girl. Aria is currently in a relationship with Ezra Fitz (Ian Harding), her former English teacher.
Shay Mitchell portrays Emily Fields. Emily is the sporty one in the group. She is the best swimmer on the swim team, and shes very sweet and loyal. Maybe a little too loyal. Emily is a shy, kind 'closeted lesbian', who was in love with Alison DiLaurentis. However, over the course of the series Emily came out to her parents that she was in a relationship with Maya St. Germain. After Maya's murder, Emily develops a relationship with Paige McCullers in season 3, they stay together for a while, until Paige betrays Emily's trust. Ali confesses her feelings for Emily in the 100th episode, but later Emily reconciles with Paige. Months later they grow apart as Paige moves to California.
Sasha Pieterse portrays Alison DiLaurentis, former "Queen Bee" of her clique and the most popular girl in school before her disappearance. She enjoys using people's deepest secrets against them to keep them in line. Charming and manipulative, Alison managed to manipulate all four of her friends in some way or another and is skilled at finding ways to blackmail others. It was revealed Alison was alive, and was on the run from "A". Months later after being back to Rosewood, Alison is arrested for Mona's murder, who she hated and bullied years ago.
Janel Parrish portrays Mona Vanderwaal, a former geek who was a constant victim to Ali's torture. However, after Alison disappeared, Mona recruited Hanna and the pair reinvented themselves as pretty, popular girls. Initially intended as a secondary character with a planned death, after her reveal as "A", Mona was upgraded to one of the main characters, and after being kicked off of the "A" team in the third season finale, she became one of the liars. Mona had two short relationships, the most prominent being with Aria's younger brother, Mike Montgomery. In the 5th season summer finale, Mona was murdered by an unknown person.
Pretty little liars season 1 episode 1 "Pilot"
Four friends Aria Montgomery, Emily Fields, Hanna Marin, and Spencer Hastings grow apart when their clique leader Alison DiLaurentis goes missing. A year later they all begin receiving messages from the mysterious "A",...
Pretty little liars season 2 episode 1 "It's Alive"
After a long night involving sleeping off the shame of being called "liars" by the entire town, the girls' parents have gathered for an intervention to send the girls to group therapy. Their shrink, Dr. Anne Sullivan, is a kind, caring...
Pretty little liars season 3 episode 1 "It Happened 'That Night'"
Five months after Mona revealed as A, the Liars are drinking at a slumber party, talking about their summer before they begin their senior year of high school. Emily, who is grieving Maya, drinks too much alcohol and goes...
Pretty little liars season 4 episode 1 "'A' is for A-l-i-v-e"
The contents of the trunk of Wilden's squad car is revealed to be a dead pig. The girls flee the scene, with Mona removing the disk showing footage of Ashley running over Wilden. In an attempt to earn some of their trust, Mona...
Pretty little liars season 5 episode 1 "EscApe From New York"
In New York, while Ezra's life is in jeopardy after being shot by 'A', Alison, Hanna, Emily and Spencer separate from Aria in order of trick 'A' and hold him away from Ezra in the hospital, however, their plan backfires. In the...
Pretty little liars season 6 episode 1 "Game on , Charles"
As Aria, Spencer, Hanna, Emily, and Mona try to escape 'A's dollhouse; they are seen by an unknown girl in a yellow top. After being trapped outside for two days, the girls are let back into the dollhouse by Charles but are attacked...
Pretty little liars season 7 episode 1 "Tick-Tock, Bitches"
Whilst searching for Hanna, the gang see Mary Drake enter the police station. They learn of her identity and that she is the new owner of the Lost Woods resort. After tricking the girls...