In Rooney’s book, all four characters are Irish, which inflects their relationships with shared cultural knowledge. The show changed this dynamic, making Bobbi a Black American and Melissa a Brit. Director Lenny Abrahamson told Vanity Fair that the decision for Bobbi came from Lane’s natural prowess in the auditions and their desire to represent the “diversity of modern Ireland.” Abrahamson also said, “We wanted to keep Bobbi even further from the rest of them. Letting her have an American accent kept her a bit more singled out.” So far, the producers haven’t commented on the decision to change Melissa’s identity.

In the book, the vacation where Nick and Frances start to hook up again after taking a brief hiatus was originally set in the South of France, but the adaptation moves the holiday to a home in Croatia instead. It’s unclear why exactly this change was made, but it’s still far too beautiful a setting for these melodramatic characters and their scandalous activities.

On their holiday in the show, Melissa senses a flirty vibe between Nick and Frances and transparently asks Frances whether there’s anything she should know about the relationship between her husband and new friend. Frances, of course, evades the question. In the book, though, Melissa comes across far less accusatory and more caring. After picking up the flirtatious energy on vacation, Melissa asks Frances to promise to tell her if Nick ever makes her feel uncomfortable. This increases the reader’s feelings that Nick is predatory and his relationship with Frances is unethical beyond its status as an affair. The show, in this moment, more squarely places Frances as the perpetrator of Melissa’s pain instead of Nick.

Frances is 21 in both the book and show, having a full 11 year age gap with Nick when they begin their affair. She is also naive and immature in both iterations of the story — constantly, and meekly, asking Nick for affirmation and apologizing profusely to him even when there is nothing for her to apologize about. Yet she is even more naive in the show — even at one point trying on Nick’s large overcoat in a scene that reads more like a child trying on her father’s clothes rather than a romantic gesture. These slight changes make it so the stark age difference and power dynamic between Nick and Frances comes into even harsher light.

Although Frances cries after having sex with Nick in both the show and book, there is one key difference between the two iterations of their first time hooking up. In the book, Frances tells Nick she’s never had sex with a man before they do the deed, but in the show, Frances admits this through tears after their sexual encounter. This makes her appear more shameful of the fact and colors the conversation as if Frances is confessing something instead of simply sharing her history.

Much like with the adaptation of Normal People, Rooney’s commentary on how classism and capitalism affect interpersonal relationships is much more direct in the book than in the show. In the series, Frances and Bobbi chat about money and allegiances to communism occasionally but in the book, Frances is often cast as the outsider for coming from a working class background and having to work to survive in Dublin. The biggest missing plot point from the book is Nick loaning Frances money when her dad ceases to send her allowance. Nick and Frances have lengthy conversations about the power dynamics present in him giving her money, although he says he would rather she have it because she actually needs it. Eventually, Frances is able to pay him back, but the weight of that power imbalance deeply imbues Frances’ feelings toward herself and Nick in the book.

Although Bobbi’s pub rant about her feminist issues with monogamy is almost verbatim from Rooney’s novel, her anger is more personal in the show. The adaptation more directly connects Bobbi’s sadness over her parents’ messy divorce to her dissolution with monogamy. Generally, compared to the book, the show gives audiences more of Bobbi’s backstory and personal traumas.

Cutting and other iterations of self-harm feature much more heavily in the book compared to the show, the latter of which only shows Frances self-harming once. In the book, Frances is often drawn to self-harm after visiting with her dad or fighting with Bobbi and Nick. These additional details add to the characterization of Frances and make the book more focused on mental health than the show.

In the book, after Frances and Nick fight about her having sex with a stranger from a dating app, they make up, have sex, and Frances asks Nick to hit her. It seems, much like her desire to self-harm, that she wants to be punished for things she feels she has done wrong, or harm she has caused to herself and others. Nick refuses and Frances feels very embarrassed, much like a very similar scene in Normal People when Marianne asks Connell to hit her during sex and he rescinds his consent out of deep discomfort. This scene from the Conversations novel is nowhere to be found in the adaptation, removing a layer that connects the two Rooney works and making Nick and Frances’s relationship a little less complicated.

The book draws out Frances’ final fight with Bobbi for a couple more scenes than the show. In Rooney’s book, Frances goes to a church to pray, faints in the pews due to her endometriosis, and is helped by a stranger. Only after this does she apologize to Bobbi and starts being honest about her diagnosis. In the show, Frances seems healthier and happier when she makes the decision to apologize to Bobbi.

Bobbi and Frances have a friend named Marianne in the book who is described as having just spent the summer in Brooklyn, leading readers to think this could be a Normal People easter egg. At the end of Normal People, Connell decides to move to New York and Marianne decides to stay in Ireland but promises she’ll visit. This unconfirmed easter egg does not feature in the new Conversations adaptation. Perhaps the creators wanted to let this project stand on its own, away from the fame of Rooney’s first adaptation.