Translation:The restaurant is in front of the school.
Both the translations Duo gave me were wrong. Note that the meaning seems to be "opposite" the school, as in "across the street from" the school. In front of the school would mean the school is behind the restaurant, i.e., you have to go through or around the restaurant to get to the school, no street in between.
This must be the worst translation yet. 'Opposite' is correct in British English. 'Across the school' is meaningless
"The restaurant is located in front of the school" should be accepted.
No, as explained above. Adding "located" is perfectly good, but not the rest. Duo is translating a Portuguese idiom too literally. If it's the same as "en frente de" in Spanish, then in English it would would have to be "opposite" or "across from" or "across the street from,. One might say "facing" or "The restaurant faces the school," but there the intent would more likely be to indicate the orientation of the entrances relative to each other rather than simply the location.
Note that these English expressions imply that the two buildings are facing each other across a space. "In front of" does not imply any space or that the front sides of the buildings are facing each other. An example with a car, for example, to show the difference. "My car is parked in front of the school" means it is on the same side of the street. "My car is parked opposite the school" means it is on the other side of the street.
The link "a + a". In front of = em frente de / em frente a. In front of the school = Em frente a a escola. Then you have to link: Em frente à escola.
Cruzi means "para + a = à" because para you can write as single "a" and then you have "a + a". It is simple to wrote one à. I never hear that idioms "de / em" work the same. I ask my teacher.
Prepositions "never" work the same.
Expressions may work the same.