The phrase 'kya hua hai tum ko' translates to 'What has happened to you' in English. It is a direct and simple inquiry often used to express concern or curiosity about someone's current state or situation. This phrase is commonly found in Hindi songs and poetry, where it serves to convey emotions of care, empathy, or surprise. The simplicity of the phrase allows it to be universally understood across different contexts, making it a versatile expression in Hindi literature and everyday conversation.