A Chinese Phrase for Asking About Someone's Birthday: "你的生日是什么时候？"

"你的生日是什么时候？" means "When is your birthday?" and it's the basic Chinese expression used to ask someone when their birthday is. It's a handy conversation starter. To answer, you can say something like "我的生日在五月。" (My birthday is in May). To wish someone well, say "生日快乐！" (Happy birthday!).