This guy beside you is using a knife. Is it correct?
It's not incorrect. I'd be more likely to say "That guy next to you is using a knife". If I were at a dinner table, I probably would not say anything - using a knife is not a thing worth commenting on, unless we're at the soup course.
Last edited by 5jj; 01-Dec-2011 at 21:37. Reason: typos -several!
Context is always important; labelling is rarely important.