One of these pronouns is the interrogative who which has the accusative form whom and the genitive form whose . Finnish, on the other hand, has fifteen grammatical cases. The number of these is often the only thing that foreigners know about Finnish. Because people find Latin with its six cases difficult, they infer that Finnish with its fifteen must be even more difficult. In fact most of the cases are very straightforward in form and function and correspond to the prepositions of the Indo-European languages.
Finnish cases have their own endings which are added to the word stem.
They can express place, time, ownership, object, manner and other such things for which English normally uses a preposition. I shall take as an example the pronoun kuka 'who'. The nominative singular is kuka . All the other forms of this paradigm begin with the syllable ke- . The original nominative ken still survives but only in old poetry and songs.