A developer from XDA Forum has figured out a work around by which you could use the Google Now service in all languages that the Jelly Bean OS supports. The dev, named Sletmo created a modified version of the Google Now app which is compatible to use in any language on Jelly Bean.
To start using Google Now in the language of your choice, you need to replace the original app with the modified version of the app which has been recoded. Also you would need the super user access to your phone, i.e, you need to root your phone.
The instructions and the download links to install this modified app are given in the source link below. But do follow them carefully and make sure you not end up damaging your device.