Makes a speech but nothing counts (6)
I believe the answer is:
orates
'makes a speech' is the definition.
(I've seen this before)
'nothing counts' is the wordplay.
'nothing' becomes 'o' (O resembles 0).
'counts' becomes 'rates' (I've seen this in another clue).
'o'+'rates'='ORATES'
'but' acts as a link.
(Other definitions for orates that I've seen before include "Speaks formally, makes speech" , "Talks grandly from a platform" , "Makes lengthy or pompous speech" , "Speechifies" , "Talks pompously" .)