En español siempre decirmos «al final», por lo que es muy fácil confundirnos con estas dos estructuras.
At the end (al final de algo)
-The shop is at the end of the streed
-I always feel tired at the end of the day
-We normally get together at the end of the year
In the end (finalmente)
-I found it in the end
-I didn’t know where to go, but in the end, I made my mind up with London
-I thought that I was going to fail the exam, but in the end, I passed it with flying colors.