Compound nouns
In Finnish, you can easily create new words by glueing two nouns together. The second part of the compound is the main word, and the first part describes it.
| This hut is too small. | Tämä koppi on liian pieni. |
| Dad bought a green nest box. | Isä osti vihreän pöntön. |
The first word's form depends on its relationship to the second word.
The genitive for purpose or user
If the first word describes the purpose or intended user of the second word, it takes the genitive case (usually ending in -n). A hut (koppi) meant for a dog (koira) becomes a koirankoppi. A nest box (pönttö) meant for a bird (lintu) becomes a linnunpönttö.
| The doghouse is in the yard. | Koirankoppi on pihalla. |
| I watched when the bird flew into the birdhouse. | Minä katsoin, kun lintu lensi linnunpönttöön. |
If the intended users are plural, the first word takes the plural genitive. For example, a room for children (lapset) becomes a lastenhuone (children's room).
| There is a big children's room in our house. | Meidän talossamme on iso lastenhuone. |
The nominative for material
If the first word describes the material the object is made of, it stays in the basic nominative case. You simply attach the two words together without any extra endings. A house made of wood (puu) is a puutalo, and a house made of stone (kivi) is a kivitalo.
| Dad built a red wooden house yesterday. | Isä rakensi eilen punaisen puutalon. |
| A stone house is really cold in the winter. | Kivitalo on todella kylmä talvella. |
This rule applies to all kinds of building materials, like lasi (glass) and lauta (board).
| The glass door broke yesterday. | Lasiovi meni eilen rikki. |
| He cried because the wooden floor was dirty. | Hän itki, koska lautalattia oli likainen. |
| The glass roof is beautiful at night. | Lasikatto on kaunis yöllä. |