es & eres
How to use es & eres? I thought
(single, feminine): es? (single, masculine): eres?
But it seems wrong when I see "Él es un niño."
Thank you for your help.
It does mean 'You', but more formally. It's just how Romanic Languages work - you use third person singular to be more formal when speaking to a stranger or someone important. E.g. you use "Tu eres un hombre" (you are a man) to say to someone you know (a friend for example) and "Usted es un hombre" (You are a man) to say the same to a stranger.