Finished what one was doing? (5)
I believe the answer is:
exact
'finished' is the definition.
(I've seen this before)
'was doing?' is the wordplay.
'was' becomes 'ex' (I've seen this in other clues).
'doing?' becomes 'act' (doing is a kind of act).
'ex'+'act'='EXACT'
'what one' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for exact that I've seen before include "Explicit" , "Specific" , "On the nail" , "Particular" , "Finished" .)