다 켜다

turn it off and on again

-았/었다 links two actions that swap back and forth, and with 끄다 and 켜다 it produces 껐다 켜다, the universal advice for a misbehaving device: 껐다 켰어요. Every single line here is that phrase. In the 껐다 켰다 form it means toggling repeatedly rather than one reboot (저희가 언어 스위치를 껐다 켰다를). Nothing about it is technical — people say it about lights and rice cookers as readily as computers.

Register: casual, everyday