Abstract nouns (-uus/-yys)

In Finnish, you can turn many adjectives (and sometimes nouns) into abstract concepts by adding the suffix -uus or -yys. This is the Finnish equivalent of English endings like "-ness", "-ity", or "-hood".

Vowel harmony determines which suffix to use: words with back vowels (a, o, u) take -uus, while words with front vowels (ä, ö, y) or only neutral vowels (e, i) take -yys.

Abstract Nouns in the Nominative Case

In their basic form, these nouns function exactly like any other noun and can be the subject of a sentence.

The Partitive Form

Because these nouns represent uncountable, abstract concepts, you will very often use them in the partitive case. This is especially common when they act as the object of verbs like etsiä (to search for), arvostaa (to appreciate), or pelätä (to fear).

To form the partitive, add -ta or -tä directly to the nominative form. The ending becomes -uutta or -yyttä.

Stem Changes in Other Cases

When you need to add other case endings—such as the genitive (-n) or the elative (-sta / -stä)—the base form changes. The final -s of the -uus or -yys suffix becomes -de-.

For example, -uus becomes the stem -uude-, and -yys becomes -yyde-.

Here, pahuus becomes pahuuden (the genitive object) because the action of defeating is fully completed.

In the last two examples, the verbs pitää (to like) and keskustella (to discuss) require the elative case. Rohkeus turns into rohkeudesta, and varmuus becomes varmuudesta.