There’s a joke about a young southern woman who is at her very first fancy dinner up north in the big city. She turns to the haughty woman next to her and says, “So, where y’all from?”
The woman replies in an arrogant tone, “We are from a place in which we do not end our sentences with prepositions.”
The young woman, taken aback at the tone and snobbery waits just a moment before returning, “Of course. So, where y’all from, witch?”
Time and again people will say that you shouldn’t end a sentence with a preposition. That’s not really true. That “rule” can lead to horribly tangled sentences that don’t reflect the way we actually speak. What you should not do is end a sentence with an unnecessary preposition.
Where are you from? Good.
Where are you at? Bad.
If you’re unsure, remove the preposition and see if the sentence sounds right and means the same thing. For instance, in the above example the meaning of the first sentence would change without the preposition. The second sentence would not.