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Hello

* 你好。Nǐ hǎo; The standard "hello" greeting.
* 您好。Nín hǎo; The same "hello" greeting as above, except that it is used for someone you treat with respect, like an elder or a teacher.
* 你好吗? Nǐ hǎo ma; More often used following a greeting than not, however, this can be used as a "hello" by itself.
* 您好吗? Nín hǎo ma; The same as the "Nǐ hǎo ma" above, except that it is used for someone you treat with more respect, like an elder or a teacher.
* 你怎么样? Nǐ zěnme yàng?; "What's up?", "How are you doing?"
* 幸会 Xìng huì! "Nice to meet you!"
* 久仰 Jiǔyǎng; An extremely polite greeting that is not commonly used between friends, but rather between professionals meeting for the first time.
* 久闻大名 Jiǔwén dàmíng; This greeting should be reserved for use towards those whom you have extreme respect for. Literal translation: "Your name is famous" / "I have heard much about you"

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Good morning

* 早上好 Zǎoshàng hǎo; Standard morning greeting.
* 早 Zǎo; Also good morning.
* 早安 Zǎo ān; Literally "Peace at morning".

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Good afternoon

• 下午好 Xiàwǔ hǎo
  
• 午安 Wǔ ān; note: seldom used in the Mainland.
  
  

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Good night

* 晚上好 Wǎnshàng hǎo
* 晚安 Wǎn ān; Literally "Peace at night".
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Good-bye

* 再见 Zàijiàn; Literally "See you again".
* 明天见 Míngtiān jiàn; Literally "See you tomorrow".
* 拜拜 Bàibài; From English "Bye-Bye". Widely used in Hong Kong, Taiwan and most urbanised parts of mainland China.
* 回头见 Huítóujiàn: roughly equivalent to "see you soon", used in northern China.
* 回见 Huíjiàn; usually used in Beijing or written Chinese.
* 再会 Zàihuì: Literally "we'll meet again". Usually used in Shanghai or other part of China, and some times used in the end of TV programme.