Strattic supports Polylang, a popular multilingual plugin for WordPress that tries to simplify managing a multilingual site. You write posts, pages and create categories and tags as usual, and then define the language for each of them.
Using Polylang with Strattic
We currently support directories, but not subdomains.
You will need to update this setting in order to ensure Polylang works with your static site.
Go to Polylang > Settings and make sure the URL Modifications are set to “The language is set from the directory name in pretty permalinks”.
When that is done, add languages and content as you normally would, when you are ready to publish, run a full publish to the static version of your WordPress site.