A little Help

Good Day to all, im having thinking to buy wd media player since all my hard disk are wd  i have 3 passport and 1 my book essential i think it may get along with wd media player. My question is how do i play mp4 file with subs srt  or ssa format without having to get with encoding or something like, if i rename it with same title will it play?  or what are the simple steps? hoping for kind response… Thank You…