In English, we often use the "dummy subject" it to introduce a statement: "It is important that..." or "It is true that...".
In Finnish, there is no word for "it" in this structure. The sentence simply begins with on (is), followed by an adjective, and then the että (that) clause. The grammatical case of the adjective changes depending on the meaning of the sentence.
Truth-Value Adjectives: Nominative Case
When the adjective states whether the että clause is a fact, certain, or proven, it usually takes the nominative (basic) case.
(Note: The word for "true", *totta, is a partitive form that functions as a fixed truth-value marker alongside regular nominative adjectives like varma).*
| It is true that this argument is bad. | On totta, että tämä argumentti on huono. |
| It is certain that this is a justified act. | On varma, että tämä on oikeutettu teko. |
Evaluative Adjectives: Partitive Case
When the adjective expresses an evaluation, opinion, or moral judgment—such as saying an action is important, acceptable, or questionable—it takes the partitive case.
Notice the partitive endings (-a / -ä or -ta / -tä) in these examples:
| It is acceptable that people live like that here. | On hyväksyttävää, että täällä eletään niin. |
| It is questionable that an ethical principle changes often. | On kyseenalaista, että eettinen periaate muuttuu usein. |
| It is moral that all people are treated fairly. | On moraalista, että kaikkia ihmisiä kohdellaan oikeudenmukaisesti. |
| It is justified that acceptable actions produce joy. | On oikeutettua, että hyväksyttävät teot tuottavat iloa. |
Infinitives as Subjects
This distinction also applies when the subject is an infinitive verb phrase instead of an että clause. Evaluating a general action as "important" (tärkeää) requires the partitive case.
| When people discuss principles, it is important to be objective. | Kun keskustellaan periaatteista, on tärkeää olla objektiivinen. |