Start with determination on, but can't finish? (3,5,2)
I believe the answer is:
get stuck in
'start' is the definition.
Both the definition and answer are verbs in their base form.
Perhaps there's an association between them I don't understand?
'determination on but can't finish?' is the wordplay.
I cannot quite see how this works, but
'finish?' could be 'tuckin' (tucking in is a kind of finishing) and 'tuckin' is found within the answer.
The remaining letters 'gets' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'with' is the link.
Can you help me to learn more?
(Another definition for get stuck in that I've seen is " Concentrate on your work!".)