How we cite our quotes: (Part.Chapter.Paragraph)
Quote #4
Yolanda, nicknamed Yo in Spanish, misunderstood Joe in English, doubled and pronounced like the toy, Yoyo—or when forced to select from a rack of personalized key chains, Joey [...] (1.4.1)
What's in a name? A person's name is pretty connected with their identity, wouldn't you say? So the fact that Yolanda has so many nicknames, in both Spanish and English, might suggest that she feels like she has a lot of different identities.
Quote #5
"I love you," John said, rejoicing, tricked by the barks and the howls.
But Yolanda was afraid. Once they got started on words, there was no telling what they could say. [...]
"Do you love me, Joe? Do you?" he pleaded. He wanted words back; nothing else would do. (1.4.13-16)
What's with Yolanda's hesitancy to say "I love you" to John? It's not because she doesn't think the words are important... in fact, it's quite the opposite. Words are super important. It's because they're so powerful that she feels like they should be careful about what they say.
Quote #6
Yo's words fell into the dark, mute cavern of John's mouth. [...] And Yo was running, like the mad, into the safety of her first tongue, where the proudly monolingual John could not catch her, even if he tried. (1.4.45)
John so does not understand Yolanda's word games. Come to think of it, there's a whole part of Yolanda that John doesn't get—the Spanish-speaking part. If John is "proudly monolingual," it means he's not really interested in getting to know that part of Yolanda. (Side note: the bit about Yolanda running "like the mad" seems like a hint about her coming breakdown and visit to the mental hospital.)