Speech marks out quest to obtain love (6)
I believe the answer is:
quotes
'speech marks' is the definition.
'quotes' can be an answer for 'marks' (quote is a kind of mark). I'm unsure of the 'speech' bit.
'out quest to obtain love' is the wordplay.
'out' indicates an anagram.
'to obtain' means one lot of letters goes inside another.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'quest' is an anagram of 'qutes'.
'qutes' enclosing 'o' is 'QUOTES'.
Can you help me to learn more?
(Other definitions for quotes that I've seen before include "Repeats as from book or speech" , "Cites as evidence" , "Uses or repeats words as from Shakespeare" , "Inverted commas" , "Identifies" .)