Informal:
* Nahi: This is the most common and informal way to say "no."
* Na: This is a shorter and more casual version of "nahi."
Formal:
* Nahin: This is a slightly more formal way to say "no."
* Nahiyan: This is the most formal way to say "no" and is used in more formal settings.
Other options:
* Chh nahin: This literally translates to "it is not," and can be used to express a negative response.
* Nathi: This is a rarer word for "no" that is sometimes used in certain areas of Kashmir.
The best way to choose the right phrase depends on the specific situation. For casual conversations, "nahi" or "na" will suffice. In more formal situations, "nahin" or "nahiyan" might be more appropriate.