Apple’s iOS 17.2 added a new option to the iPhone 15 Pro‘s Action button with the ability to start a translation. Here’s how to do it, and how to pick the language you want.
You could already have set your Action Button to run Apple’s Translate app, by writing a Shortcut. All that would do, however, is literally run the app, launching you to its front screen and then leaving you there.
Whereas now with iOS 17.2 and later, you can press and hold the Action Button for a moment, then say something in English and immediately have its translation.