Could someone who is conversant with English grammar please clarify this: If a friend and I are looking at a photograph in which I appear among a hundred other people, my friend might say: "Which one (person in that group) IS you?" But my friend would say: "There are good people and bad people in this world. Which (one) ARE you?" Is there some rule to explain this difference? A MILLION thanks in advance. (P .S. Will the rules -- I need rules -- permit me to say: (referring to that photo) Which one ARE you? My answer: I AM the person standing under the tree.)
I'm not a teacher.
A while ago I had a similar problem.
I hope I can help you now.
When you say "Is you", you must remember that the "is" belongs to another word. A person is you. (is belongs to person) You are a person. (are belongs to you) Good people and bad people are (are belongs to them all)
You must always check the word/words which is/are linked with the is and are.