Be there at the start and finish (6)
I believe the answer is:
attend
'be there' is the definition.
(I've seen this before)
'at the start and finish' is the wordplay.
'start' says to take the initial letters.
'and' is a charade indicator (letters next to each other).
'finish' becomes 'end' (synonyms).
The initial letter of 'the' is 't'.
'at'+'t'+'end'='ATTEND'
(Other definitions for attend that I've seen before include "Listen carefully" , "put in an appearance" , "Listen closely" , "Go regularly to (school)" , "Pay heed" .)