Affirmative: I’m interested in photography. He / She / It ’s interested in photography. You / We / They ’re interested in photography.
Negative: I ’m not Italian. He / She / It isn’t Italian. You / We / They aren’t Italian.
Questions: Am I funny? Is he / she / it funny? Are you / we / they funny?
Short answers: Yes, I am. Yes, he / she / it is. Yes, you / we / they are. No, I’m not. No, he / she / it isn’t. No, you / we / they aren’t.