How do you say hi goodbye and thank you in Chinese?

Fine answers, but don't forget there are a couple dialects of Chinese. Most of the answers are in Mandarin dialect that are spoken in most of mainland China, and Taiwan. But in Macau, Canton (on the mainland), and Hong Kong, folks speak Cantonese. Good bye in Cantonese sounds something like 'joy geen' and Thank you sounds something like 'daw jeh'. If you want to say: Hello, Beautiful, it sounds something like 'Nay ho, leng loy? (to a female)' or 'Nay ho, leng jai?' (to a male). [caution, pronunciations are calibrated for speakers of American English]