Linda is an observant, intelligent girl growing up in a small Southern town. She experiences a form of synesthesia that causes her to taste words, a condition she keeps hidden from her family. To cope with her overwhelming sensory experiences and social isolation, she focuses on her studies and forms deep bonds with a select few people. She eventually moves to New York City to study law.

Harper is Iris's younger brother and Linda's great-uncle. He works as a librarian at nearby Gardner-Webb College. He stands out from the rest of the traditional conservative family with his sing-song voice, love of dancing, and bachelor lifestyle. His unique speaking style makes it easier for Linda to process her synesthesia around him.

Kelly is Linda's energetic and precocious childhood best friend. The two girls bond over their shared secrets, their love for Dolly Parton, and their observations of the adults around them. They maintain a steady correspondence through handwritten letters even as they grow older and their social circles shift.

Thomas is Linda's father, a pragmatic lawyer who comes from an old, wealthy North Carolina family. Unlike his relatives who study law merely to protect their assets, Thomas chooses to actively practice it. He is a reasonable and steady figure who provides a sense of security for his family.

DeAnne is Linda's mother and the daughter of Iris Burch. She maintains a tense, distant relationship with Linda, struggling to demonstrate maternal warmth. She adheres tightly to Southern conventions and the expectations of her strict upbringing, often preferring to avoid difficult conversations or emotional vulnerability.

Iris is DeAnne's mother and Linda's grandmother. She is a rigid traditionalist who views family relationships through a lens of obligation and duty rather than affection. She commands respect through her blunt honesty and her insistence on maintaining appearances in their small Southern town.

Wade is a boy who lives in Linda and Kelly's neighborhood. He shares a morning bus stop with Linda for years before they begin to interact meaningfully. As they enter adolescence, Wade becomes a central figure in the girls' social awareness, representing the transition from childhood friendships to teenage romance.

Leopold, known as Leo, is a medical student studying psychiatry who comes from an old Northern family. He meets Linda during her adult life in the Northeast. His pragmatic approach to life and his appealing name, which tastes like parsnip to Linda, draw her to him.

Bobby is an older, high school-aged boy in the neighborhood. He works doing yard maintenance for local families. His imposing physical presence and crossing of boundaries create an atmosphere of unease for the younger girls when he works near their homes.