The illative case (-Vn, -hVn, -seen)

Asking "Where To?"

When you want to ask where someone is going, you use the question word mihin (where to). It specifically asks for a destination rather than just a static location.

The Illative Case (Moving Into)

To answer mihin, you use the illative case. This case expresses moving into or to a destination. The ending you use depends on the word, but it always ends in an -n:

• -Vn: Simply lengthen the final vowel of the word and add -n. This is the most common ending (e.g., koti becomes kotiin).
• -seen: Often used for longer words ending in two vowels, or words like huone (e.g., Lontoo becomes Lontooseen, huone becomes huoneeseen).

Matching Cases

Adjectives must match the noun they describe. If your destination noun is in the illative case, any adjective attached to it must also be in the illative case.

You will also sometimes see the -hVn illative ending. This is typically used for short words ending in two vowels (like maa, which becomes maahan).

Staying "Into" a Place

In English, you stay in a place. In Finnish, logic dictates that your movement stops and you are left into a place. Because of this, the verb jäädä (to stay) always requires the destination to be in the illative case.

Plural Adjective Agreement

Adjectives must also match their nouns in number. If the subject of your sentence is plural, both the noun and any adjectives describing it must take the nominative plural -t ending.