Data input in any of these languages is natively understood. It is then processed and rendered in the same language. No translation of your data will take place.
It is essential that you specify the language of your dataset when uploading a new project, which the system will prompt you to do in the Language drop down menu before being able to create the project.
To specify a different language from the Analytics web interface, use the Language dropdown selection on the New Project page. To specify a different language when uploading via the API, use the languages parameter under the recalculate docs endpoint.
An incorrect language setting for a built project cannot be changed from the Analytics web interface; you would need to build a new project with the corrected setting. From the API, you can recalculate the project again with the corrected language parameter.