Which of these sentences is correct / more common / formal?
For what did he win a Nobel Prize?
What did he win a Nobel Prize for?
Which of these sentences is correct / more common / formal?
For what did he win a Nobel Prize?
What did he win a Nobel Prize for?
For what did he win a Nobel Prize?
Very correct, very formal.
What did he win a Nobel Prize for?
More colloquial. Also very dependent on context &/or emphasis.
Taken at face value, & also when written, it asks the same question as the first version… but with emphasis on he it could indicate the speaker is wondering why the Nobel committee thought he was deserving of an award.