Turning on subtitles/closed captioning varies slightly depending on how you are watching videos. 

Computer / Desktop Browser

If subtitles are available, you can select the CC icon in the lower right corner of the player and choose a language:                                                                     

iOS & Android App

If subtitles are available, you can tap the subtitles icon on the bottom right corner of the player and select the language of choice:

tvOS

1. Load the video.
2. Swipe down on the touch surface on your remote.
3. If available, the subtitle option will appear and a list of the subtitles available will appear below it.
4. Select the subtitle option.

Roku

1. Press the Home button on the Roku remote.
2. Scroll to the Settings option and select it.
3. Scroll to the Accessibilityoption and select it.
4. Select Captions Mode and select your preferred subtitle mode.

Amazon Fire Devices

1. Select a video to watch and start playback.
2. Press the Menu
3. Select Turn Subtitles On.
4. Press Menu again to go back to the video.