The 'Site Language' setting affects small pieces of system text that your visitors see in your site's blog, the Simple Blog subscription feature, Simple Store, and social feed sections - e.g. "Return to site" button for the blog, "View More" link for social feed, Simple Store's buyer flow and email notifications to buyers.
** This feature will not change any of the content you've entered!**
To change your Site Language, go into your editor's Settings panel, select "Basic Info", and then Site Language. You'll see the window below, in which you can choose from 16 languages (other than English).
Select the Site Language that matches your site content, and click "UPDATE". Once you republish your site, the Site Language change will be reflected.
Here are 2 contrasting examples to illustrate the effect of changing your Site Language -
1. For this blog, the Site Language has NOT been changed to match the site content (simplified Chinese). Notice the English 'Return to site' button in the top left -
2. But for this blog, the Site Language HAS been changed to match the site content (French). The 'Return to site' button in the top left is nicely in French -
Providing a smoother, more cohesive user experience for that user's French audience :)