A mensch is someone you like and admire, especially because they have been good to you — kind, honest, and ready to do the right thing when it would have been easier not to. “What a mensch” is warm praise. “Be a mensch” means “do the decent thing.” English took the word from Yiddish, where it means an honourable person. That Yiddish word came from older German words for a human being, and the English spelling followed German Mensch. Though actually, German Mensch often just means “person.” English mensch is warmer and more moral: not anyone alive, but someone who behaves like a good human being. You hear it most in American English, especially in Jewish families and in New York talk. It is friendly, a little old-fashioned in a kind way, and not formal. People now say it of women as well as men. You will not hear it much in a Taiwan classroom; you will meet it in American films, books, and conversation. It sounds like “mensh.”