How do I set my iPhone to prefer English for texting?

I have an iPhone 14 pro. I mainly use English, but also use Italian. I had both languages set up in my language settings, but the interface and predictive text for texting are in Italian. I would like them to be English. I couldn't work out how to make the 'phone prefer English, so I deleted Italian from my language settings. However, the text interface and predictive text are still Italian. This problem is only happening for texting. Other apps (WhatsApp, for example) are in English. How can I change texting to English?

[Re-Titled by Moderator]