He writes about state (it is in German) (8)
I believe the answer is:
essayist
'he' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'about state it is in german' is the wordplay.
'about' is an insertion indicator.
'state' becomes 'say' (to state something is to say it).
'it is in german' becomes 'esist' (I've seen this in another clue).
'say' inserted inside 'esist' is 'ESSAYIST'.
'writes' is the link.
Can you help me to learn more?
(Other definitions for essayist that I've seen before include "Writer of short literary pieces" , "Bacon maybe" , "One who writes short pieces on given subject" , "Montaigne, say" , "Writer of shorter pieces" .)