Easily apply a language to a range
When you change the language, PowerPoint also looks at the language setting of your keyboard, resulting in a different setting than you tried to select.
Maybe there's a corporate policy for English: should users always select ' English (United Kingdom)' instead of 'English (United States)'?
KeySlides helps: the administrator sets the supported languages (and their variations) users can select.
In KeySlides, you click the Spelling button, select one of the available languages and choose where to apply
the setting: the whole presentation, the current slide, or the selection on the current slide?
If you choose Presentation or Slide, the language setting will also be applied to the notes page.