Sole college question on English (6)
I believe the answer is:
unique
'sole' is the definition.
(I've seen this before)
'college question on english' is the wordplay.
'college' becomes 'uni' (I've seen this in other clues**).
'question' becomes 'qu'.
'on' means one lot of letters go next to another.
'english' becomes 'e' (abbreviation).
'uni'+'qu'+'e'='UNIQUE'
(Other definitions for unique that I've seen before include "Individual" , "Without equal, unparalleled" , "Singular, not like any other" , "incomparable" , "Being the only example" .)