कौन  —     किस —     क्या —

कौन  pro) who, which

किस  pro) oblique singular form of कौन

किसे/किसको  pro) whom, to whom, to which, to what

किस तरह (से)  in what manner, how

किन  pro) oblique plural form of कौन 

किन-किन  how many, which ones

कौनसा/कौन-सा/कौन-सी/कौन से  what, which (one)

कौन-कौन सी  which ones

क्या/किस/किसे/किसको  pro) what; to inquire about a fact, situation, etc., usually at the beginning of a sentence