I have a friend who taught kids with autism and told me that they were taught to say “person with autism” so I’ve always gone that route since then.

“Person with autism” is something neurotypical researchers cooked up to describe our “disease” that we need to be “treated” for. Like we’re a person with the flu, or a person with asthma. It implies that we’re fundamentally broken in some way. It’s very common in clinical or educational circles. Your friend probably didn’t know any better, and the kids they were teaching didn’t, either.

“Autistic” or “Autist” is how we talk about ourselves. Autistic folks aren’t sick or broken—we’re whole people. Being autistic is who we are.