"The boy sleeps in the city."
Translation:Puer in urbe dormit.
The verb doesn't have to be at the end of the sentence; that's just where the course creators chose to place it. Latin word order is very free, so you can put "Puer dormit in urbe" like you would in French or Spanish and it would be perfectly fine. Be sure to report something if you think that it should be accepted, since this course is still very new.
Would there be a word such as "urbi", like there is a single word for "at home" ("domi")?