FromProto-Finnic*-ic'ëC, consisting of the suffix*-icci plus an additional consonant. The additional consonant is only found in Finnish; the other Finnic languages have forms deriving from the vowel-final form. Cognate withEstonian-itsi,Karelian-ičči,Veps-iči.
-itse
Although commonly analysed synchronically as-tse added onto the plural stem of the word, in origin the suffix simply began with-i- (like-inen), and no plural stem was involved.
Most grammars treat the prolative not as a separate case because it seems not to occur inconcorded form (an adjective inPROLATIVE + a noun inPROLATIVE); allegedly only with nouns in this form (e.g.postitse(“by post”);puhelimitse(“by phone”); etc.). However, there is one example which makes the prolative pass the concord test and therefore makes thePROLATIVE a case:
Despite this, the prolative is widely held to be an adverbial case, not a proper case.