Speak is the story of Melinda Sordino, a high school freshman. She tells her story in her own words, in the present tense. This telling seems to be a kind of internal monologue. Melinda doesn't talk much to others, but she sure hasn't stopped talking to herself; she does lots and lots of thinking about her problems, and we get access to all of her thoughts.
We might think of Speak as a glimpse into Melinda's mind as she figures out how to deal with the fact that she was raped. Seen in this way, the novel makes a subtle argument for thinking, or talking to one's self as a means to solve problems. Melinda's intense reflections on her inner and outer worlds lead her to certain conclusions. Perhaps most importantly, she concludes that she has a moral obligation to warn others about her attacker and that telling the story to others is necessary for her own healing.
When we're dealing with first-person narrators we have an important question to ask: Is this narrator reliable? Should I believe what she's telling me? In the case of many first-person narrator's (like Edgar Allan Poe's – seriously, check out "The Tell-Tale Heart"), the answer is "heck no." But what about Melinda?
We'd tend to say that Melinda is a reliable narrator because she's basically talking to herself. There's no question that she's trying to trick the readers, or hold back important information. In fact, she's doesn't really seem aware that there are readers, unlike the narrator of "The Tell-Tale Heart," who addresses the readers directly, trying to convince us that, though he is a murderer, he's not insane.
On the other hand, Melinda is unreliable. She's bitter, angry, self-destructive, and self-deceptive. She's rightly upset with how she's being treated by her schoolmates, parents, and teachers, but her anger is also blinding. She sees others as belonging to a different species than she does. She rarely uses people's names. Andy is "IT;" her teachers are Hairwoman and Mr. Neck; her principal is Principal Principal.
This helps make Speak fun to read, but it also highlights the fact the Melinda is figuring out her feelings. To do that, she has all kinds of strategies for creating distance between herself and others. So, we'd say it's safe to trust this narrator, but not some of the generalizations she makes about the people around her.
We'll leave you with a question: Does Melinda change as a narrator from the first day of school, when the novel begins, to the last day of school when it ends?