Multilingual comments form missing
The i18n comments can be used for this.  From the project page:


  A very simple module which would allow you to show all/any comments
  attached to all node translations. Just a great way to communicate in
  truly multi-lingual environments.
  
  For example I have node in English and Spanish. Drupal natural way
  would be to show comments for en/es translation separately (attached
  to en/es content). But i18n_comments will aggregate all English and
  Spanish comments for any translations. It doesn't matter if user will
  leave a comment to any node translation.