Sets one's sights higher and improves (5,2)
I believe the answer is:
looks up
'sets one's sights' is the definition.
The definition and answer can be both to do with communicating as well as being verbs in their -s form.
Maybe they are linked in a way I don't understand?
'higher and improves' is the wordplay.
'higher' becomes 'up'.
'and' is a charade indicator (letters next to each other).
'improves' becomes 'looks' (I am not sure about this - if you are sure you should believe this answer much more).
'up' after 'looks' is 'LOOKS UP'.
Can you help me to learn more?
(Another definition for looks up that I've seen is " Seeks in reference book - takes eyes off book".)