Does he not allow cash when you pay for drinks? (9)
I believe the answer is:
bartender
'does he not allow cash when you pay for drinks?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'does he' is the wordplay.
I cannot really understand how this works, but
'he' could be 'bart' and 'bart' is present in the answer.
The remaining letters 'ender' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for bartender that I've seen before include "Local worker" , "American serving drinks" , "One serving" , "Liquor salesman" , "source of 9 [ROUND] ?" .)