To change the language on your iPhone, you can follow these steps:
1. Open the Settings app on your iPhone. The Settings app icon looks like a gear and is typically located on the home screen.
2. Scroll down and tap on "General."
3. In the General settings, scroll down and tap on "Language & Region."
4. Tap on "iPhone Language" at the top of the screen.
5. A list of available languages will appear. Scroll through the list and tap on the language you want to use.
6. A pop-up message will appear asking if you want to change the language. Tap on "Change to [selected language]" to confirm.
7. Your iPhone will then prompt you to enter your passcode to confirm the change.
8. Once you enter your passcode, your iPhone will restart and apply the new language settings.
After your iPhone restarts, the language throughout the operating system and default apps will be changed to the language you selected. Keep in mind that third-party apps may not automatically switch to the new language and may need to be updated individually within their settings.