"I do not know where your fish are."
Translation:Jeg ved ikke hvor dine fisk er henne.
´Henne´ connotates a static place, it would translate as ´at´ in English. Here some more information about it: https://forum.duolingo.com/comment/4821593/Hvor-er-du-henne
I think the 'henne' is similar to what the Americans say - 'I do not know where your fish are at'.
I found these links: https://www.duolingo.com/dictionary/Danish/henne/d92d5698a860a4524519f897dedb9a67