The winner of the competition is the person who gets the cheese first, which is the prize.
closed as off-topic by Janus Bahs Jacquet, Ellie Kesselman, Marv Mills, Nicole, Centaurus Mar 13 '15 at 23:10
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Proofreading questions are off-topic unless a specific source of concern in the text is clearly identified." – Janus Bahs Jacquet, Ellie Kesselman, Marv Mills, Nicole, Centaurus
Yes it is just about grammatical. The reason I hesitate is that the word first gets in the way, between cheese and its relative pronoun which, making the whole thing a bit clumsy.
It would perhaps be better to say The winner is the first to get the cheese, which is the prize. That way it is perfectly grammatical.
The relative clause should be immediately after the noun it modifies:
The winner of the competition is the person who gets the cheese, which is the prize, first.
See Grammar Bytes for a tutorial on the user of the relative clause.
I will correct the sentence to make the relative clause after the noun:
The winner of the competition is the first person who gets the cheese, which is the prize.