impersonal with se
Ustedes no permiten fumar en el museo.
2 Answers
Ustedes no permiten fumar en el museo.
This says "You (all) don´t permit smoking in the museum."
There are two ways to make this impersonal:
"No permiten que fumas en el museo" (They don´t allow you to smoke in the museum). This is impersonal but it´s active voice because "they" dosen´t identify anyone in particular. As far as "fumar" is concerned, it can conjugated to any person you choose without changing the basic case of the sentence.
"No se permite fumar en el museo" (Smoking is not permitted in the museum). This is also impersonal, but passive voice.
"Personal" and "impersonal" are just words in grammar books, but "active" and "passive voice" are real grammar cases.
This lesson might help you - The Spanish 'se' and it's many meanings and uses
Feel free to post your attempt changing your example to an impersonal sentence and we'll be happy to check it for you.