Estonian locative system

The Estonian language has six locative cases, descended from the locative cases of Proto-Finnic. They can be classified according to a three-way contrast of entering, residing in, and exiting a state, with two sets of cases: inner and outer.

System	Entering	Residing in	Exiting
Inner	-sse "into"	-s "in"	-st "from "
Outer	-le "to"	-l "on / at"	-lt "from "
State	-ks "into as"	-na "as"	-nt "from being as"

For some nouns, there are two forms of the illative: the regular suffix -sse, added to the genitive stem, and an alternative, short form, which is either consists of a different suffix, lengthening, and/or another change in the word. The always regular -sse illative ending is a newer innovation, and can sometimes have a slightly different meaning than the old "short form" illative, the latter having the concrete locative meaning, and the former being used in other structures that require the illative.