"The girls in school are quiet."
Translation:Puellae in ludo sunt tacitae.
It seems to me that this should be rendered in English as "the girls are quiet in school" rather than "the girls in school are quiet", since this latter would want something like a relative clause: "tacitae sunt puellae quae in ludo sunt".
The Latin "puellae in ludo tacitae sunt" is telling us WHERE the girls are silent, rather than WHICH girls are silent, or, to put it another way, the prepositional phrase "in ludo" qualifies the verb, not the noun.
I welcome corrections on this matter, of course.