There are various options depending on the requirements and technical limitations.
If you are able to put the language of the user in the URL you can use a filter webpart and connect it to the view web part. The view web part then filters the results based upon a value comming from the filter web part.
In the SharePoint on premise version. You can program your own "connected webpart". This way you have full control over where to get the language information of that user.
A third option.
Create two audiences. One for english users and one for the german users. You can configure webparts so they are only visible if the user is in a certain audience. When the audiences are created you put two list view webparts on a page, set the filters correctly and set the audience in the web part properties. One list view web part is only displayed to english users. The other one is only displayed to german users.