asks: I'm planning to write a book with four POV characters. However, it's all in first-person. How do I make all the voices distinctive so they don't all sound the same?

Before we get into character voices, I'd like to suggest that each chapter be titled with the name of the POV character's name. Otherwise it will be very confusing for the reader to figure out who's talking since the story is in first person, even if we use distinctive voices.

An affectation is a particular behavior or attitude that isn't natural, often displayed in an effort to impress or humor others. For example, someone may love to speak in hyperbole and exaggerate everything they say. Instead of "a driver cut me off on the freeway today," they might say, "this car swerved out of nowhere and practically ran me off the road! I almost died!"

Think about gestures that some people habitually make while speaking. Maybe they wave their hands around a lot, maybe they mumble a lot, or maybe they don't make much eye contact. Some people laugh too much when they're nervous. These are different ways to make a character feel like a person rather than a cardboard cutout.

Speech patterns refer to the way someone expresses themselves when they speak. These could be accents (refer to Question 71: Accents if you want more information on writing accents), repeated phrases, or favored word choices. Maybe someone could, like, pause in their talking a lot to, like, use the word "like" a lot. Maybe a character likes to say "BOOM" every time he makes a point. Another character could overuse the phrase "it is what it is" at every opportunity.

The next time you're hanging out with a group of friends, observe them like an anthropologist might. Watch what they do with their hands. See how one person tends to dominate the conversation more than others. Maybe he or she likes to cut off other people in order to voice their own opinions. Listen for noises of acknowledgement that people make instead of speaking. For example, mm-hmm or cough-insults. Intentionally observing group interactions like this is a great way to store a little reference guide in your head for the next time you need to imagine different characters talking to each other.