Sulked quietly inside but cleaned the floor (6)
I believe the answer is:
mopped
'cleaned the floor' is the definition.
'mopped' can be an answer for 'cleaned' (mopping is a kind of cleaning). I'm not certain of the 'the floor' bit.
'sulked quietly inside' is the wordplay.
'sulked' becomes 'moped' (I've seen this in another clue).
'quietly' becomes 'p' (p for piano and quiet).
'inside' means one lot of letters goes inside another.
'moped' going around 'p' is 'MOPPED'.
'but' acts as a link.
Can you help me to learn more?
(Other definitions for mopped that I've seen before include "Sponged (up)" , "Swabbed (floor)" , "Cleaned or wiped with bundle on end of stick" .)