“Er … Steve, I’m confused - finish your sentence!” (5,4)
I believe the answer is:
serve time
'finish your sentence' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'er steve i'm confused' is the wordplay.
'confused' indicates an anagram.
'er'+'steve'+'im'='ersteveim'
'ersteveim' anagrammed gives 'SERVE TIME'.
Can you help me to learn more?
(Other definitions for serve time that I've seen before include "as one behind bars may do" , "undergo a term of imprisonment" , "Be in prison" , "go to gaol" .)