ka:- ka/

ka is occasionally used alone as an indefinite pronoun, especially in negative sentences (e.g. na kasya ko vallaBaH, no one is a favourite of any one;
nAnyo jAnAti kaH, no one else knows;
kaTaM sa GAtayati kam, how does he kill any one?) Generally, however, ka is only made indefinite when connected with the particles ca, cana/, cid, vA, and a/pi, in which case ka may sometimes be preceded by the relative ya (e.g. ye ke ca, any persons whatsoever;
yasyE kasyE ca devatAyE, to any deity whatsoever;
yAni kAni ca mitrARi, any friends whatsoever;
yat kiMca, whatever).
The particle cana, being composed of ca and na, properly gives a negative force to the pronoun (e.g. yasmAd indrAd fte kiMcana, without which Indra there is nothing), but the negative sense is generally dropped (e.g. kaScana, any one;
na kaScana, no one), and a relative is sometimes connected with it (e.g. yat kiMcana, anything whatsoever). Examples of cid with the interrogative are common; vA and api are not so common, but the latter is often found in classical Sanskṛt (e.g. kaScid, any one;
kecid, some;
na kaScid, no one;
na kiMcid api, nothing whatsoever;
yaH kaScid, any one whatsoever;
kecit — kecit, some — others;
yasmin kasmin vA deSe, in any country whatsoever;
na ko ‘pi, no one;
na kimapi, nothing whatever). ka may sometimes be used, like kad, at the beginning of a compound. See ka-pUya, &c.