Formal:
* വ്യസ്തനാണ് (vyastanaanu) - This literally means "is busy" but can be used for both singular and plural subjects. You can also use the plural form വ്യസ്തരാണ് (vyastarannu) if you are referring to multiple people.
* തിരക്കുള്ളതാണ് (thirakkuḷḷathāṇ) - This translates to "is busy" but focuses on the presence of activity or work.
* ജോലിയിലാണ് (jōliyilaanu) - This means "is at work" and implies that the person is occupied with their tasks.
Informal:
* തിരക്കുണ്ട് (thirakkuṇṭ) - This is a shorter and more casual way of saying "busy".
* കുഴപ്പമില്ല (kuḻappamilla) - This literally means "no problem" and is a common way of declining an invitation or request by saying you're too busy.
Examples:
* ഞാൻ വ്യസ്തനാണ് (ñaan vyastanaanu) - I am busy.
* അവർ തിരക്കുള്ളതാണ് (avar thirakkuḷḷathāṇ) - They are busy.
* അവർ ജോലിയിലാണ് (avar jōliyilaanu) - They are at work.
* എനിക്ക് തിരക്കുണ്ട് (enikku thirakkuṇṭ) - I am busy.
* എനിക്ക് കുഴപ്പമില്ല (enikku kuḻappamilla) - I am busy (and can't do that).
It's important to choose the appropriate phrase based on the situation and the person you are speaking to.