Hello!. How are you? Thank you very much again!
Can I use the genitive in this sentence?
1.- He is at the end of a corridor.
2.- He is at a corridorīs end.
In the non-genitive way is correct too, isnīt it?
Have a marvelous Saturday night!
Did you learn it as "the genitive case"? That isn't really a good term for it. I prefer to talk about "the possessive form".
There is a general rule -- although it's not a very strict one -- that you use the possessive form for people and often animals, and the construction with "of" for inanimate objects. Like this:
The business-woman's briefcase.
The handle of the briefcase.
Both your sentences are okay, but sentence 1 sounds much, much better.