After work can choose to take part (3,2)
I believe the answer is:
opt in
'choose to take part' is the definition.
(to opt in to something is to choose to take part)
'after work can' is the wordplay.
'after' means one lot of letters go next to another.
'work' becomes 'op' (common abbreviation for 'opus').
'can' becomes 'tin' (synonyms).
'op'+'tin' is 'OPT IN'.
(Other definitions for opt in that I've seen before include "Choose to be included" , "Choose to participate" , "Join voluntarily" , "Choose to take part" , "be involved voluntarily" .)