Did Planche do his own work in translating from languages other than French?
Evidently not. He spoke a little German, but evidently only on a basic level, and was more or less competent in Italian, but seems unlikely to have managed the nuanced understanding necessary to do a good translation. In these languages (for melodramas and operas), he relied on other people’s scholarly work. In Greek, for his classical burlesques, he possessed a fair reading knowledge, but again based his work on English translations, not on the originals. He did read Latin well enough to translate directly; however, his Classical works, for the most part, drew upon Greek sources.