I am an English assistant and I often hear my non-native students say:
I often buy fruits when I go to the supermarket.
I think it is wrong logically because "go" means "to move or travel from one place to another" (source). I am not sure whether it implies "you are already there"
Should we change to:
I often buy fruits when I am at the supermarket
but it does not say that "I go to the supermarket".
How do native speakers express that idea?
Note: when could mean "after", so, I often buy fruits when I go to the supermarket=I often buy fruits after I go to the supermarket
Best Answer
In the context of running errands, go to (some place) is idiomatic speech, and it means more than the physical act of going to that location. So, when I “go to the store,” I don’t merely park in a parking spot and then go home; rather, I go into the store – presumably to purchase some items.
Similarly, when you go to the dentist, you go inside and get your teeth cleaned; when you go to the barbershop, you get your hair cut; and when I go to the bakery, I’m probably not going just to smell the aroma of fresh-baked bread – I’m most likely buying some of that bread and taking it home with me.
Therefore, there is nothing illogical about what your students are saying – although, as other answers have said, most native speakers would use fruit instead of fruits.