Meaning of vendeur/vendeuse with qualifying adjective

Question

Why is a sales ASSISTANT, referred to as vendeur? A salesperson ( un vendeur) is different than a subordinate salesperson assistant. I used the qualifying adjective and it was marked wrong.

Accepted Answer

MS, 
the confusion here is probably partly due to regional differences in English usage. 
In French retail  ‘ vendeur/vendeuse ‘ are the terms (most) used, whatever we might call the ‘ sales person ‘ or ‘ sales assistant ‘ or ‘ shop assistant ‘, or any of the other regional English variations.
In many parts of the English speaking world ‘ sales assistant ‘ is one way of referring to ‘ salesperson ‘.  An ‘ assistant salesperson ‘ would most likely be referred to as exactly that, indicating they are an assistant to another salesperson. I don’t recall ever coming across someone with that job title but can see how it could apply to a new, junior appointee, perhaps in training.
See wordreference links for different English expressions for the same position covered by ‘ vendeur/vendeuse ‘ in French. 
https://www.wordreference.com/fren/vendeur
 https://www.wordreference.com/enfr/salesperson

Answer

Just to add to what Maarten said, I think a sales assistant is assisting the customer, not another salesman.