Verb Rections: The Illative Case
In Finnish, many verbs "govern" their accompanying nouns, requiring them to be in a specific case regardless of the English translation. This is called verb rection. Several verbs describing orientation, reaction, or commitment demand the illative case (the "into" case, usually ending in a lengthened vowel + -n, -hVn, or -seen).
Adapting and Settling
The verbs sopeutua (to adapt) and tyytyä (to settle for) require the illative case for the environment or situation you are adjusting to.
For example, erämaa (wilderness) becomes erämaahan, and leiri (camp) becomes leiriin.
Adjectives modifying the noun must also match in the illative case. For example, karu todellisuus (harsh reality) becomes karuun todellisuuteen.
Consenting and Resorting
When navigating reality show politics, you will also use suostua (to consent to) and turvautua (to resort to). Like the adapting verbs, these also take the illative case for the thing being agreed to or relied upon.
Words ending in -s, like petos (betrayal), often have an illative ending in -kseen (e.g., petokseen).
Making Alliances
Not all strategic verbs take the illative. When forming teams, you use the verb liittoutua (to ally oneself). To specify who you are allying with, use the postposition kanssa, which requires the preceding noun or pronoun to be in the genitive case (like kenen, the genitive of kuka).