Yes, it’s normal to only stutter in one language. I’ve seen numerous people on this subreddit that only stutter in one language, but not the other. Personally, I stutter in both the languages I speak, and more in my second language because I feel self-conscious when speaking something that is not my home culture (I learned the language and am still learning it). I think the reason is that each language has a set of memories, and feelings associated with it. It even has a personality associated with it. Not only because of the culture that you tap into while speaking it, but because of your experiences with that language. Maybe you have various negative experiences with your parent, speaking this language, so it triggers you. Maybe you mostly spoke that language as a child, so when you speak it now, you feel like a child and that feeling doesn’t match up with your current age. So your whole internal system gets thrown off. And for reading, maybe you don’t stutter because the words aren’t your own. So you trust the words more. But you become triggered when you have to be creative and tap into your own identity to speak extemporaneously. And the fact that you’re using the word “Extemporaneously” might show that you might be a bit of an over-achiever (That’s a big word that I had to look up). If so, where does that come from? Do you learn words like this out of interest, or because you feel incompetent so want impress other people? Or? Maybe you are a little bit rigid in your thinking, and although not totally a bad thing, it’s something you will have to learn as far as relating to other people who are less rigid. Because feeling relatable to others creates an easier flow of spontaneous speech. So I would really recommend the Dave McGuire course. They have an inexpensive self help book on Amazon called “Beyond Stammering: The Mcguire Program for getting good at the Sport of Speaking.” You can have the book downloaded onto your phone in minutes if you get the Amazon Kindle app. The book will go through psychological reasons for stuttering, give you a breathing technique, and inspire you to get out and practice speaking. The program will be fear inducing but use the people closest to you for support. Keep practicing the techniques and follow what the book says. Then I recommend reading “Redefining Stuttering” by John Harrison, someone who stuttered for many years and was part of the National Stuttering Association for many years. You can find a free link to the book if you google the title. If you can’t find it I will help send you a link. I was surprised to find the book for free after seeing it was sold out on Amazon.