To turn subtitles ON, do the following:
1. From the Video Player, click on the blue Settings bar, located next to the Volume Settings
2. Make sure you have chosen the correct subtitle language and that it is currently translated to 100%, as shown below
3. From the Show Subtitles option, slide the button to the right, to turn on the subtitles on this video
Subtitles are usually turned ON and set to English by default (or whatever site language you currently have turned on). If you don't see any subtitles showing on the screen, make sure the chosen language is translated to at least 90% before you start watching.