Plelase help me to find mistake

[nose]

Only I and my friend were at the concert.
Correct Only my friend and I were at the concert.
thank you

[naomimalan]

It wouldn't be considered correct to say "Only I and my friend were at the concert." This is because, when I am talking about myself (I) and somebody else (my friend) I should put myself (I) last: "only my friend and I".

I suppose it's a question of good manners.