WonderFox Free HD Video Converter Factory is a good and free program for adding subtitles to MKV. It can quickly add SRT to MKV through hardcoding or softcoding. As the cherry on top, it will add subtitles to videos without watermark. With the same program, you can also add subtitles to other video files as well as remove subtitles. The whole process is only a couple of clicks.
Now, download and installdownload and install this freeware, and learn how to add subtitles to MKV.