Formal:
* 恭喜 (gōng xǐ) - This is the most common and general way to say congratulations.
* 恭喜您 (gōng xǐ nín) - This is a more polite and formal way to say congratulations, adding "you" at the end.
Informal:
* 祝贺 (zhù hè) - This is another way to say congratulations, but it is slightly less common than 恭喜.
* 恭喜恭喜 (gōng xǐ gōng xǐ) - This is a more informal and celebratory way to say congratulations, often used in festive occasions.
Other specific situations:
* 恭喜发财 (gōng xǐ fā cái) - This literally means "congratulations on making money" and is often used during Chinese New Year.
* 恭喜结婚 (gōng xǐ jié hūn) - This means "congratulations on getting married."
* 恭喜生子 (gōng xǐ shēng zǐ) - This means "congratulations on having a child."
The best way to choose the right phrase depends on the situation and your relationship with the person you are congratulating.