Finnish

Suffix

-itse

1. by, through; the suffix of the prolative, determines the channel by which something takes place.

   • meri ‎(“sea”) → meritse ‎(“by sea”)
   • sähköposti ‎(“email”) → sähköpostitse ‎(“by email”)

Usage notes

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.

Some grammars treat the prolative not as a separate case because it seems not to occur in concorded form (an adjective in PROLATIVE + a noun in PROLATIVE); 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 make the PROLATIVE a case:
Hän hoiti asian pitkitse kirjeitse. -- He took care of the matter with a long letter.

Derived terms