In the Pretty Little Liars book series, Alison DiLaurentis (Sasha Pieterse) has a twin sister named Courtney who switches places with Ali. Though the PLL Powers That Be have said that they are not exploring the twin storyline, we think it makes a lot of sense especially given how Alison seems like she has two very distinct personalities (one mean girl, one loyal friend). Here are five instances when we think “Ali” was actually her nicer, saner sister.

“You know, I should really do something about ‘A.’ That bitch is genuinely getting on my nerves.”

In Season 1, Episode 11: “Moments Later,” “Ali” visits Hanna in the hospital after she has been hit by a car. This is her first appearance following her “death.” In the books, Courtney and Ali were bitter enemies, and we think that could be the case in the show, as well, given Courtney’s line to Hanna: “You know, I really should do something about ‘A.’ That bitch is genuinely getting on my nerves.” It makes sense that “A” could stand for Ali. We think it might be Courtney who visits Hanna in this scene, and that she is complaining about her own twin sister.

“I’m pretending to be someone else.”

In Season 2, Episode 18: “A Kiss Before Lying,” Hanna remembers a time when she ran into “Ali” at a hair salon. She is wearing a brown-haired wig and pretending to be someone called Vivian Darkbloom. She tells Hanna, “Here’s the thing: I’m pretending to be someone else, so play along… Cause I’m bored. I do it a lot. You should try it sometime. I mean, aren’t you just sick and tired of being you?” We assumed this was Ali talking about pretending to be Vivian, but what if it was Courtney talking about pretending to be Ali? She might not have been exaggerating when she said she does it “a lot.”

“How about forever?”

There are lots of reasons a teenage girl might fantasize about running away especially with someone with as screwed up a life as the DiLaurentis twins seemed to have. But, if Courtney really did manage to switch places with her twin sister, she probably knew it was only a matter of time before someone figured it out. In Season 3, Episode 18: “Dead to Me,” Emily remembers a conversation she had with Ali about running away to France together for “forever.” We think Courtney fantasized about getting away before something terrible happened.

“Honey, you didn’t even know me when you knew me.”

In Season 3, Episode 23: “I’m Your Puppet,” “Ali” visits a sleep-deprived Spencer at Radley. Not only is it telling that the girl knows exactly how to sneak into and around Radley (in the books, Ali convinced everyone that Courtney was mentally unstable, and Courtney spent three years at Radley), but that she tells Spencer, “Honey, you didn’t even know me when you knew me.” We’re actually unsure if this twin is Courtney or Ali, but we do think it proves there are two of them.

“Would you ever disown any of them, your children?”

In Season 2, Episode 11: “I Must Confess,” Spencer remembers “Ali” all-out grilling Hanna’s grandmother, Regina, about what it would take for her to disown a child. At the time of the recollection, Spence thought Ali was trying to get Jason written out of their grandmother’s will, but now we think it was Courtney and that she either a) trying to get Ali out of their grandmother’s will or b) trying to figure out if she was written out the will. A third possibility is that this really was Ali in this scene, and she was trying to get Courtney written out. In the books, Ali frames Courtney as mentally insane. Could Ali have tried something similar in the series?

Do you think it was Ali or Courtney in the above scenes? Sound off in the comments below!

Catch the Pretty Little Liars Season 4 Halloween special on Tuesday, October 22, 2013 at 8 p.m. ET on ABC Family.

Credit: Celebified Photo: Pretty Little Liars Halloween Special "grave New World" Preview Photos: Ezra Lurks In The Shadows While The Girls Search For Ali!