This is the 5th most frequent Marathi word.
क
The Marathi word "क" is the first consonant in the Marathi alphabet and represents the sound "ka."
In this sentence, 'क' is a prefix used in the question word 'कधी' to ask about time.
तू कधी वाढदिवस साजरा करतोस?
When do you celebrate your birthday?
Here, 'क' forms the question word 'का', indicating a reason or cause, equivalent to 'why' in English.
का तू अभ्यास करत नाहीस?
Why don't you study?
In this instance, 'क' is used at the beginning of the question word 'काय', meaning 'what' in English.