Reduce studies in first chapter? (8)
I believe the answer is:
condense
'reduce' is the definition.
(condensing is a kind of reducing)
'studies in first chapter?' is the wordplay.
'studies' becomes 'dens' (I've seen this before).
'in' means one lot of letters goes inside another.
'first chapter?' becomes 'cone' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'dens' placed within 'cone' is 'CONDENSE'.
(Other definitions for condense that I've seen before include "contract?" , "Decrease, reduce" , "Summarise" , "Send once (anag.)" , "Turn from gas to liquid" .)