Where an extraterrestrial had some lessons? (4)
I believe the answer is:
eton
'where an' is the definition.
The definition suggests a singular noun which matches the answer.
'extraterrestrial had some lessons?' is the wordplay.
'extraterrestrial' becomes 'et' (I've seen this in other clues).
'had' says to put letters next to each other.
'some lessons?' becomes 'on' (I can't explain this - if you can you should give a lot more credence to this answer).
'et'+'on'='ETON'
Can you help me to learn more?
(Other definitions for eton that I've seen before include "School - note (anag)" , "Independent school" , "British public school of note" , "Easy to understand" , "Place for learning" .)