She hadn’t even said anything nice about him. She hadn’t told him that he was prettier than any girl, and that his skin was like sunshine with a suntan.
And that’s exactly why she hadn’t said it. Because all her feelings for him—hot and beautiful in her heart—turned to gobbledygook in her mouth.

This quote, which is from Chapter 19 and Eleanor’s perspective, comes when Eleanor and Park are having their first long, private conversation. Eleanor doesn’t have a phone in her house, but Eleanor and Park get the opportunity to talk when Eleanor babysits her dad’s son and she has access to her dad’s phone. Before telling Park how much he means to her, Eleanor hasn’t even had a chance to articulate to herself exactly how she feels about Park. This is a milestone in her life, and a big deal given that Eleanor has an especially difficult time admitting her feelings to both herself and to Park. She has much more practice in building a wall between herself and others so that she can stay protected from the world around her. This is in part due to her mother’s toxic relationship with Richie.

Eleanor and Park experience the connection between them as more deeply intertwined than the crushes the other kids in school have on one another. They are feeling emotions that they haven’t yet experienced in their lives, and they are also figuring out how to express these to both each other and themselves.

The quote is also evidence of the ambiguity in gender expression that both Eleanor and Park demonstrate, since Eleanor often refers to Park as being beautiful, a term most often used to describe girls, and Park admires that Eleanor wears men’s clothes.