I'm a bit baffled by what you're trying to accomplish exactly. But if you're supposed to be able to access the same post and see it in a different language, does that imply some automated translation?..in which case the language preference would only be a session/user/display setting, instead of storing the language and translated text. If the translations are done by hand, that's a different story.
To help clarify your database schema it's best to draw an ER diagram rather than straight into specific schema. You should be able to walk the pen along the relationship lines in the ER diagram, as you work through functional scenarios of your app. ER diagram shows the cardinality ( 1-to-many etc) about the relationships between the tables, so helps clarify the relationships and remove basic anomalies (e.g. many-to-many cardinality needs refactoring)