This is my favorite and most frequently-used method of adding subtitles to MKV and other videos. Every time I have the need to add subtitles, I will turn to Free HD Video Converter Factory, and it will never let me down. It can successfully add subtitles to videos with a few clicks without any quality loss. Of course, if I have to remove the subtitle from MKV, Free HD Video Converter Factory is still my first choice.
Now, download and installdownload and install this freeware, and learn how to add subtitles to MKV.