Change the language on your iPhone or iPad - Apple Support

You can change the language setting on your iPhone or iPad if it's incorrect or if you've accidentally changed the language to one you don't understand.

Modify files, folders, and downloads in Files on iPhone - Apple Support

Translate text, voice, and conversations on iPhone - Apple Support

How to Change App Language on Your iPhone or Mac

Translate text, voice, and conversations on iPad - Apple Support

Use Markup to add text, shapes, signatures, and more to documents on iPad - Apple Support

Select, cut, copy, and paste text on iPhone - Apple Support

Find settings on iPad - Apple Support

How to customize VoiceOver pronunciations on your iPhone or iPad - Apple Support

Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support