I had a great deal of excitement about using FirstBook to create my first draft and then edit it. Of course, I knew that Spanish (my native language and the language of my audience on the social networks where I plan to sell my book) might be an issue. I found that in the outline stage I could write everything in Spanish, but when I moved on to the phase of writing chapter by chapter, I ran into error after error. I spoke with Casper, and he told me that I should change, or rather translate, everything into English, which is a big problem for me. I did it anyway, and even then I kept having problems. I decided to stop using it. It would be very expensive to translate an entire book from English to Spanish.

I believe I can do everything in my native Spanish with the new ChatGPT 5.5 model or Claude Opus 4.7 in Codex. Please don’t take my criticism the wrong way. I think FirstBook is a great tool, but they should make it very clear that it only works 100% in English. Spanish is spoken by more than 450 million people around the world. Unless I receive a response from Casper saying that Spanish will be included very soon, I’m afraid I will request a refund. Those who plan to use it in English will have no problem. I will change my review if everything changes very soon.