MKVs often have multiple languages "burned-in" or attached as separate tracks.
: If the file won't open at all, it may have downloaded incompletely. Try re-downloading it from the original source. A quick DVD to VOB to MKV conversion guide - PCR's notepad
If you need to play the file on a smart TV or share it where MKV isn't supported, converting it to MP4 is best. : Open VLC and go to Media > Convert / Save . Add your MKV file and click Convert / Save . Select a profile like Video - H.264 + MP3 (MP4) . Choose a destination and click Start .