Formal:
* 您好 (nǐ hǎo): This is the most common and polite greeting, suitable for formal situations like meeting someone for the first time, addressing elders, or in business settings. It literally means "You are good," but it's used as a general greeting.
* 贵姓 (guì xìng): This literally means "What is your surname?" It's used when you want to ask someone's last name in a formal setting.
Informal:
* 你好 (nǐ hǎo): This is the same as the formal version, but can be used in more casual settings.
* 嗨 (hāi): This is a more informal greeting similar to "hi," but not as common as "你好" (nǐ hǎo).
* 你好吗 (nǐ hǎo ma): This means "How are you?" and is a friendly way to greet someone.
Other options:
* 早上好 (zǎo shàng hǎo): This means "Good morning."
* 下午好 (xià wǔ hǎo): This means "Good afternoon."
* 晚上好 (wǎn shàng hǎo): This means "Good evening."
It's best to start with "您好 (nǐ hǎo)" or "你好 (nǐ hǎo)" unless you are familiar with the person and are sure that a more informal greeting is appropriate.