ko-ko- को को]_: Repetition of the interrogative particles. We use the repetition to express the fact that the answer has a plural meaning. The same process exists in languages such as Mongolian (from the same author: Introduction to the Mongolian Language - www.voyagemongolie.com).
Who is in your family? तपार्इको परिवारमा को को हुनुहुन्छ ?
Which languages do you speak? तपार्इ कुन कुन भाषा बोल्नुहुन्छ ?
Who is at your home? तपार्इको घरमा को को छन् ?
What things are available in this shop? यो पसलमा के के पार्इन्छ ?
On which days does Nepal have holidays? नेपालमा कुन कुन दिन बिदा हुन्छ ?
How often do you take a bath? तपार्इ काठमाण्डौंमा कहिले कहिले जानुहुन्छ ?