In the event that your Kindle's menu is not your preferred language, this can be updated easily in your Kindle's settings.
- Click the three dots at the top right of your kindle to open the dropdown, and then select "Settings", separated from other options in the menu by a horizontal line.
- Look for the globe icon, and tap "Language & Dictionaries".
- Select the first option, "Language".
- Tap "English (United Kingdom)".
- Choose "OK" to confirm the change and restart the Kindle.