Nikola Nikolov

paiyakdev

This plugin separates the user comments by the language they viewed the article in – this way you avoid duplicate content(which is frowned-upon from search engines) and comments in other languages than the one the current visitor is using(which is generally bad user experience).
You can manually change the language of each comment(and you will have to set it in the begining).
Bulk-editing of the comments language is also available.
The plugin is using comment-meta to specify the language for each comment, so nothing will break if the plugin is deactivated.
It also should work out-of-the-box for all themes that use the comments_template() function to render their comments.
The plugin also fixes an issue of qTranslate. The issue consists in the fact that whenever a user posts a comment(while viewing a post in a language different than the default one), he is redirected back to the post but in the default language and not the language he was reading the post before posting the comment.

qTranslate(-X) Separate Comments

Automatically separate the user comments by the language they viewed the article in.

Guido Eugenio aka Zhenya

mqTranslate Separate Comments is a fork of the qTranslate separate comments plugin, extending the original software with collaborative and team-oriented features.
This plugin separates the user comments by the language they viewed the article, in this way you avoid duplicate content (which is frowned-upon from search engines) and comments in other languages than the one the current visitor is using (which is generally bad user experience).
You can manually change the language of each comment (and you will have to set it in the begining). 
Bulk-editing of the comments language is also available.
The plugin is using comment-meta to specify the language for each comment, so nothing will break if the plugin is deactivated.
It also should work out-of-the-box for all themes that use the <code>comments_template()</code> function to render their comments.
The plugin also fixes an issue of mqTranslate. The issue consists in the fact that whenever a user posts a comment (while viewing a post in a language different than the default one), he is redirected back to the post but in the default language and not the language he was reading the post before posting the comment.

mqTranslate Separate Comments

Automatically separates the user comments by the language they viewed in the article.

qTranslate(-X) Separate Comments vs mqTranslate Separate Comments