To translate subtitles, Khan Academy translators use YouTube’s Fan Captions tool. This allows you to take the existing English-language captions, and translate the text into your language. To subtitle, following these steps.
1) Go to Khan Academy Translation Portal, and select your language.
2) Select “Subtitles” from the menu on the left.
3) Choose a subject, for example, "Math", and then select a video (see goals and milestones here) on the right that needs to be translated.
4) This will bring you to YouTube’s Fan Captions tool. If there are no English captions to translate, please contact email@example.com.
5) You can start to translate now! For more functions, follow the directions displayed in this video starting at 0:22 to get started.
6) It'll automatically be published when it gets enough reviews.