Definition from Wiktionary, the free dictionary
declension of तू
- तू is least formal way of expressing "you" in Hindi and is used when addressing those of much lower social status or those one has a close enough relationship with to justify the reduced formality. Because the less formal forms could offend others, आप is the safest way to express "you" unless there is reason to be less formal. The usage of तू varies. In some cases speakers would use it to refer to babies or children or even close friends, while others would use it only to refer to those they consider socially inferior, and some consider its use for people to be very rude in any situation. However तू, when used to address deities reflects a sense of reverence and closeness commensurate with the lack of formalities.