The very same change in dialect (9)
I believe the answer is:
identical
'the very same' is the definition.
(I've seen this before)
'change in dialect' is the wordplay.
'change' is an anagram indicator.
'in'+'dialect'='indialect'
'indialect' is an anagram of 'IDENTICAL'.
(Other definitions for identical that I've seen before include "Impossible to tell apart" , "Matching" , "lacking distinction" , "as B and B" , "Equal" .)