Learn some new vocabularies?


I just came across the following passage on the Facebook page of an English language school: “Week in Review - Learn some new vocabularies by reading about what happened in the world. Leipzig English wishes you a lovely weekend.”

Why would they use the plural ‘vocabularies’ instead of ‘words’ or the singualar ‘vocabulary’ or vocabulary words’ or ‘expressions’? I mean, isn’t the plural ‘vocabularies’ rather rarely used in certain context when talking about specific sets of vocabulary words?

Maybe the post was written by a German who just translated the word ‘Vokabeln’ as ‘vocabularies’?