I am not a native speaker.
I am doing the exercise "Put the words in the correct order to make question" from my workbook.
I have this set of words:
your / best / see / did / friend / when / last / you?
And I have three variants of the question:
- When did you see your best friend last?
- When did you see last your best friend?
- When did you last see your best friend?
Which variant is correct and natural? Why?