How to burn non-English subtitles into mkv using a mac application?
Handbrake a great application for dealing with video on the Mac. Handbrake can burn in subtitles and create both MKV and MPEG-4 files.

The Handbrake wiki contains more information about what is possible with subtitling:


  HandBrake can use subtitles tracks as INPUT from the following sources:
  
  
  From DVD’s – Either embedded VOBSUB or CC tracks. 
  From Bluray - PGS Subtitles. 
  User supplied SRT files. 
  From Files (such as mkv or mp4)
  Embedded subtitle tracks. 
  
  
  HandBrake has two methods of subtitle OUTPUT: 
  
  
  Hard Burn: This means the subtitles are written on top of the image permanently. They cannot be turned on or off like on the DVD.
  Soft Subtitles: This means the subtitles will appear as separate selectable tracks in your output file. With the correct playback software, you’ll be able to enable / disable these subtitles as required.