Greasy Fork is available in English.
Use similar controls as on YouTube when watching Showtime (`f` for full screen, `k` to play/pause, `c` for captions, `m` to mute/unmute, `p` to enable/disable PiP, `j`/`l` to go back/skip 10 seconds, left/right arrows for 5 seconds, `0`..`9` for 0% .. 90%)