In ancient language he has to make the coffee (6)
I believe the answer is:
hebrew
'in ancient language' is the definition.
'Hebrew' can be an answer for 'language' (Hebrew is an example). I'm unsure of the 'in ancient' bit.
'he has to make the coffee' is the wordplay.
'has' means one lot of letters go next to another.
'to make the coffee' becomes 'brew' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'he'+'brew'='HEBREW'
Can you help me to learn more?
(Other definitions for hebrew that I've seen before include "Middle Eastern language" , "Jewish language" , "Israel's official language" , "Language of ancient Palestine, still used in Israel" , "Ancient Semitic language, used in modern version in Israel" .)