The Babel extension lets you add language boxes to your user page.
See the extension page on MediaWiki.org for more info: mw:Extension:Babel
Example:
{{#babel:da-0|de-1|he-2|es-3|fr-4|it-5|en|pl-n}}
Note if you are using VisualEditor, adding this may not work as expected. You should add it in the source editor.