"There is a restaurant on this street."
Translation:في هٰذا ٱلْشّارِع مَطْعَم.
As a rough guide, if you want to bring the attention to "something" then use Hunák followed by that noun or thing. In the case here, we can say (hunák maT3am ...etc) meaning there is a restaurant.....
However, Hunák is rarely, if not never, used before a preposition (unless you put a pause, a coma or something to separate it from the following phrase). Thus you might say هناك مطعم في هذا الشارع or في هذا الشارع مطعم or even في هذا الشارع هناك مطعم - but هناك في هذا الشارع مطعم would sound a bit weird unless you separate it like: هناك، في هذا الشارع، مطعم
This exercise makes me crazy. Not enough I translate between three languages in my head, and three languages from three totally different logic, because from three different language families I am close to no chance to find out what this sentence wants from me and I keep making it wrong even with word bank! Frustrating! I'll make a screenshot of the solution and check it every time I got this sentence. Annoying! I understand that that's why this sentence is here to teach us this kind of sentence, but I keep making mistakes and it makes me angry! :) I know: good that this is my biggest problem at the moment :D and also good that language learning can be frustrating sometimes. Don't worry, I don't give up! (yet... ;) :D )