"They are buying something at the supermarket."
Shouldn't it be 在买 to indicate this is an action in progress? I.e., buying
Maybe, but I think what they really meant was "to buy something" rather than "buying something"
I'm not sure. At first I thought like you it seemed correct, and maybe at some technical level it is. But then I thought, rather like in English when words are repeated, folk get lazy and the accepted usage doesn't bother with the extra words.
At least that's how my Chinese wife explained it...
Same question. Is there a way to distinguish "They are buying something at the supermarket." and "They buy something at the supermarket."?
If it was 在买 then it would be "currently buying", because zai comes from 正在，to be doing the action at that moment.
The English should have been, "They are at the supermarket to buy something"
Remember location comes before action in Chinese, so the sentence is about buying, not being at a place.
So this literally means they are at the supermarket, buying something as suggested by other ppl in different post