Something to work on constructively (4)
I believe the answer is:
site
'something to work on constructively' is the definition.
I can't judge whether this definition defines the answer.
'something to work on' is the wordplay.
'something' becomes 'it' (I've seen this in other clues).
'to work' becomes 'se' (I can't explain this - if you can you should give a lot more credence to this answer).
'on' means one lot of letters goes inside another (as in clothing \'on\' a person).
'it' going inside 'se' is 'SITE'.
Can you help me to learn more?
(Other definitions for site that I've seen before include "station" , "Locate, position" , "Whereabouts" , "Somewhere to build, perhaps" , "Area set aside for building" .)