Formal:
* വ്യസ്തനാണ് (vyastanaanu) - This is the most common and formal way to say "busy." It literally means "occupied" or "engaged."
* തിരക്കിലാണ് (thirakkilaanu) - This means "in a hurry" or "in a rush."
Informal:
* കുഴപ്പമില്ല (kuzhappamilla) - This literally means "no problem," but it is often used to politely decline an invitation because you are busy.
* സമയമില്ല (samayamilla) - This means "no time."
Example:
* "I am busy today."
* Formal: ഞാൻ ഇന്ന് വ്യസ്തനാണ് (Njaan innu vyastanaanu)
* Informal: ഞാൻ ഇന്ന് കുഴപ്പമില്ല (Njaan innu kuzhappamilla)
The best way to choose the right phrase is to consider the context of the conversation and the level of formality.