can't swim
They don't know how to swim.
अंधेरा और तूफान था और मुझे तैरना नहीं आता था।
It was dark and stormy, and I didn't know how to swim.
— Roma (2018)
He/She doesn’t know how to swim.
I can't swim properly.
उसे तैरना नहीं आता था और उसके पास जीवन-जैकेट भी नहीं थी।
He didn’t know how to swim, and he didn’t have a life jacket either.
He doesn't know how to swim!