Friendship
As its title indicates, the theme of friendship is central to Ferrante's novel. Because of the frame narrative structure, which presents the events of Elena and Lila's childhoods retrospectively, readers know that the friendship endures over the course of the two women's lives. The long time span of the novel, relaying events from the two girls' childhood and adolescence, also reveals the friendship’s formative influence on each of them. Because it began when both were children, the friendship shaped Lila and Elena into the people they would be as adults. Most interestingly, however, the novel presents the friendship in ambivalent terms: it is painful and sometimes destructive, especially for Elena. While romantic relationships are often presented as turbulent in literature, friendships, especially between women, are usually given fairly positive representation, so Ferrante's novel is somewhat unconventional in calling attention to the darker aspects of female friendship.
Education
As they grow up, Lila and Elena receive two parallel but different types of education. They are given formal education in a schoolroom setting, where the knowledge they acquire is laid out according to a structured and perhaps somewhat antiquated curriculum. At the same time, their observations of the people and events happening around them provides them with a potentially more important type of education: an awareness of motivations, desires, interconnections, and vulnerabilities. This divide is heightened after Lila ceases her formal schooling when her parents decide that they cannot afford to continue paying the fees. Elena's education focuses on academic subjects, including Latin and Greek, whereas Lila's education comes from observing the people around her and coming to understand their motivations and behaviors.
Jealousy
Many characters in the novel display forms of jealousy. In particular, Lila and Elena tend to be jealous of each other. Elena often envies Lila for her courage, her ability to stand up for herself, and for the intuitive way in which she learns, even after her formal education comes to an end. As they get older, Elena also becomes jealous of Lila's alluring effect on on men. Although it is less explicit, there are hints that Lila envies Elena for being able to continue her studies; Lila follows along as Elena studies more complicated subjects. Jealousy is also a source of tension in the neighborhood; as the Solara brothers become more successful and wealthier, many of the young men in the neighborhood are jealous of them for being able to afford things like their car.
Community
Community is a major theme in the novel: the residents of the neighborhood where Lila and Elena grow up form a world unto themselves. There is little contact with individuals who live in other areas, and since most families live in the neighborhood for generations, old feuds and rivalries linger on for decades. The close-knit community can be oppressive and is often marked by violence. At the same time, it creates a strong sense of belonging, and while members of the community may fight amongst themselves, they can also be fiercely loyal if attacked by outsiders. This pattern is most visibly illustrated when Rino and Enzo get into a fight with some young men from a different neighborhood and are rescued by the Solara brothers.
Writing
The act of writing is foregrounded in the novel when, in the frame narrative, Elena describes opening her laptop and beginning to transcribe her memories of her life with Lila. What follows is thus explicitly presented as a written text, not simply a world into which the reader enters. As children, Elena and Lila's fascination with stories leads them to write a "novel," and later Elena is deeply impressed to learn that Donato Sarratore has written a book of poems. For Elena, writing is a source of power and a mark of status, something that she associates with a more sophisticated and intellectual world outside of the neighborhood in which she has grown up. When she is given the opportunity to write an essay critiquing religious dogma in a political journal, she hopes that this will signal her intellectual capacity and impress Nino. At the same time, because of the hopes she attaches to it, writing can be a source of disappointment. When Elena learns that her article was not published after all, she feels crushed. She is also disappointed and saddened whenever she reads Lila's writing, as she feels that is naturally far better than her own, and serves to reinforce the sense of inferiority she often feels.
Violence
The rough nature of the neighborhood where Lila and Elena grow up leaves them exposed to violence from a young age. They witness quarrels, attacks, and are aware of the murder of Don Achille. This exposure to violence gives them a sense that the world is volatile and unstable, and that one must always be on one's guard. Lila and Elena can also be personally subject to childish acts of violence, such as having rocks thrown at them, or to physical abuse from their families, such as when Lila's father throws her out of the window, breaking her arm. As they grow older, threats of violence take on a sexual element; it is clear that they are at risk of being raped or assaulted, and Lila in particular is prepared to defend herself and Elena with physical force.
Money
Lila and Elena grow up relatively poor, and fantasize about what they might do with money. Even from a young age, they understand how money translates into the capacity to own prestigious physical objects (such as fancy clothes or the Solara brothers' car) and also how it creates power and access to a wider range of choices. Lila in particular dreams of her family becoming rich, and this is a major motivation for her plans to begin designing and manufacturing shoes. Her family, however, sees a different path to wealth, and part of their desire for Lila to marry Marcello is rooted in the financial security they think this will provide. Lila is ambivalent about how her marriage connects with money; she will not marry Marcello for his money and she rejects the idea that Stefano can use his wealth to win her heart. At the same time, she is very proud of the advantages that being engaged to Stefano gives to her.
