Illatiivis

Illatiivis, or illative, is a grammatical case in Finnish that marks direction toward the interior of a place or object. It is used with nouns to express going into or toward the inside of something, especially with verbs of motion such as mennä (to go) or tulla (to come). Examples include Menen taloon (I am going into the house) and Hän menee kaupunkiin (He goes to the city). The illative can also appear in idiomatic expressions to indicate a destination or target.

Formation and varieties: The illative is formed by adding a suffix to the noun stem. The suffix has several allomorphs, chosen according to vowel harmony and the stem’s ending. Common singular forms include -oon (talo → taloon), -iin or -in (kaupunki → kaupunkiin), and -aan/-ään or -jaan (kirja → kirjaan). The plural illative attaches similarly, yielding forms such as -oihin (talo → taloihin), -ihin (kaupunki → kaupungeihin), and -iin (kirjat → kirjoihin).

Relation to other cases: The illative is one of Finnish’s locative cases, contrasted with others such as the inessive (in, -ssa/-ssä), elative (out of, -sta/-stä), and allative (to the surface or toward, -lle). The exact form is determined by phonology and vowel harmony, and some stems require memorization due to irregularities.

Examples (singular and plural):

- talo → taloon (to the house)

- kaupunki → kaupunkiin (to the city)

- kirja → kirjaan (into the book)

- maa → maahan (into the ground)

- talot → taloihin (to the houses)

- kaupungit → kaupungeihin (to the cities)

- kirjat → kirjoihin (into the books)

The illatiivis forms enable precise expression of movement toward inside a place and are integral to standard Finnish grammar.