Character Clues
Character Analysis
Actions
You might expect us to say that type of being is a tool of characterization in this book—after all, we're dealing with two alien races and humans—but one of the main points of this book is arguably that appearances can be deceiving. And since this is the case, it all boils down to actions. Actions are one of the main ways that characters not only reveal themselves to us, but also break through the barriers of prejudice with each other. Check this out:
The Boov had invaded our planet, erased our monuments, taken our homes, and dumped us in a state they didn't want, and I was already so used to the whole idea that it seemed like a sweet gesture that they hadn't left us to starve in the dark. (3.1042)
Tip thinks she's got the Boov all figured out, right? But when J.Lo comes along and saves her butt, she's forced to rethink things. His actions on an individual level defy Tip's generalizations about the Boov—and as they do, we realize that all the other generalizations in the book are up for grabs, too. For an interesting comparison, you might consider how favorably Tip generally feels about humans alongside the actions of Daniel Landry and Vicky.
Speech and Dialogue
In case we ever forget, speech is used to remind us who is human and who is not—and since the world has been invaded by aliens, this helps place characters in terms of where they fall in the battle for control over the planet. The aliens, for the record, don't possess the same mastery of English as the humans, and the Gorg seem to always be yelling.
But this isn't the only way that speech helps us understand characters. It's also used to reveal how people are dealing with the current state of affairs, which helps us get a better sense of the post-invasion climate since we're otherwise stuck inside Tip's head.
So when Daniel Landry says, "Gratuity, you need to trust in your leaders. I know you kids might not think that's 'cool,' but the Gorg have a lot to offer us" (3.1369), we know immediately that he's pretty attached to trying to run the show. And when Vicky says, "I think you kids don't understand what's happening […] We can't all go around doing our own thing and… and changing everything!" (3.407), it's clear she's freaking out.
These are only a few examples. Can you think of others?