Learn Finnish: Jos hän ohittaisi toisen auton radalla, me olisimme innoissamme. - If he overtook the other car on the track, we would be excited.

This is a state adverbial built from the noun into (enthusiasm). To say someone is "in a state of enthusiasm", Finnish uses the plural inessive form (innoissa-, literally "in the enthusiasms") and attaches a possessive suffix that matches the subject. Because the subject is me (we), we add -mme, resulting in innoissamme.

Why is "the other car" written as toisen auton instead of being in the partitive case?

The verb ohittaa (to overtake or pass) usually describes a complete, finished action. Because he would be completely overtaking the entire car, the object is a total object. It takes the genitive-looking accusative case (toisen auton) rather than the partitive.

Why do both verbs, ohittaisi and olisimme, contain the -isi- marker?

The -isi- marker indicates the conditional mood, which usually translates to "would" or expresses a hypothetical situation. In Finnish, unlike English, both the "if" clause (Jos hän ohittaisi...) and the result clause (...me olisimme...) must be in the conditional mood.

What is the base dictionary form of radalla, and why did the spelling change?