"You are in the market."
Translation:Vos in foro estis.
I think this is an example of words changing their meanings over time and in new contexts.
The word forum in classical Rome meant the assembly area where people would meet to buy and sell and conduct business.
Mercatus is where we get the word merchant from, and meant a person instead of a place.
You go to the forum to see a mercatus.
A “forum” in English is still a location, so I’m not sure what you mean by changing meanings in this case. Words do indeed change meanings, but “forum” hasn’t much in my opinion.
And “mercatus” is also a “marketplace”. The person would be a “mercator,” with the common -tor suffix used for ppl.
It is, indeed, acceptable, but also not necessary, as I am sure you know, judging by your name, Magister. I have been a Magistra for 42 years I did not use a pronoun, since they are most often omitted. I also used the 2nd singular form of the verb to be. It was considered incorrect, but it was not. I think I will wait until the bugs are worked out of this before using it with students.
I have another gripe. I would like to comment not just on this sentence, but on all the DL pre-recorded Latin sentences generally, but I have tried to send comments like this before to DL and no one replies! Why is it that all these recorded sentences sound so pompous - as though Horace or Cato were making a speech: "How many boys and girls do you teach?"? Also, why do they always sound as though they were speaking inside a box?