People from different backgrounds, or different places, speak in different manners. This can take the form of a different accent, altered vocabulary, or variation in how a sentence is constructed. Accents are difficult to convey in writing, and when attempted are often annoying to the reader. For example, I have relatives that pronounce the word chair with two syllables (chay-are). I know of no way to put that in writing that isn’t both awkward and confusing. So it’s best to focus on the other two methods and simply mention when someone has an accent.
Consider the following sentences:
- Dontcha worry, Audrey.
- Don’t you worry, Audrey.
- Don’t worry, Audrey.
- Do not worry, Audrey.
- Be not concerned, Mistress Audrey.
The first example uses English slang, which is a way to make someone sound informal (and less educated). The second example sounds more folksy than the third because of the added (and unnecessary) you. The fourth differs from the third simply by dropping the contraction, and it is a simple way to make a character sound more formal. The final example is designed to sound extremely formal, pretentious even.
Simple word choice can help to differentiate characters. Where one person might say “okay”, another might say “all right”. Something might happen “a lot”, “often”, or “frequently”, depending on who is speaking about it.
Deciding on just how a character should speak is a challenge, and the way they speak might change over time or even depending on who they are speaking with. (Think about how most adults simplify their language when talking to small children.) But it is definitely something that a writer needs to keep in mind.