Answer: there is an error in sentence 1.
Where is the band playing their concert at?
I don’t know up with how much more I can put.
I liked the company for which I was working for.
When will you arrive at the opening gate?
A preposition is a word that informs you of time or location.
When will you arrive at the opening gate?
The sentence above is the one with the preposition. The word at is the preposition. It answers the question of where you are arriving.
Hope this helped!
