Some people can speak easily.

Some people always have difficulty speaking.

Some people never speak at all.

Some people can speak, but at a cost that’s not worth it.

Some people are better off communicating in other ways.

Some people speak sometimes, and type other times.

Some people have words all the time; some don’t.

Some people can speak fluidly, but only on certain topics. (Just like how one can be fluent in some topics in a foreign language, but be unable to read the news).

Some people lose speech at certain levels of stress.

Some people rely on hand movements and stimming in order to find words.

Some people have a monotone and convey tone through motion.

Some people make a lot of mistakes with words, and rely heavily on tone to make themselves understood.

Some people rely heavily on scripts, and only sound normal when they stay on-script.

Some people use phrases from television.

Some people communicate by repeating themselves, and tend to be perceived as not communicating.

Some people say a lot of words they don’t understand, and are perceived as having meant them.

Some people substitute one word for another a lot, and don’t always realize it.

Some people can answer questions even when they’re having trouble initiating speech.

Some people who find speech easy sound odd.

Some people who find speech difficult sound normal.

You don’t really know how someone communicates until you’ve communicated with them substantially, and even then, you only know in the context you’ve communicated in. Appearances can be deceiving. 

And it’s important to be aware that all of these things exist.