Witty type, cheerful and flash (6,5)
I believe the answer is:
bright spark
'witty type' is the definition.
I know nothing about this answer so I can't tell whether this works.
'cheerful and flash' is the wordplay.
'cheerful' becomes 'bright'.
'and' means one lot of letters go next to another.
'flash' becomes 'spark' (spark is a kind of flash).
'bright'+'spark'='BRIGHT SPARK'
Can you help me to learn more?
(Other definitions for bright spark that I've seen before include "Lively and clever individual" , "ironically, one that's witty" , "Clever person" , "one who has many good ideas" , "One full of ideas" .)