elementary number theory - Can $n - 1$ divide $n$, where $n$ is a positive, composite integer?

If $n$ is a positive and composite integer, can I prove that $n - 1$ does not divide $n$ for all $n$?

If not, can you give me a counter example?

• I was trying to prove it by contradiction, but I was just running in a vicious circle.

Any hint or solution please?