Breakdown of Kun me miekkailemme, me testaamme toinen toisemme refleksejä.
me
we
toinen
other, another; second
kun
when (conjunction)
testata
to test
Questions & Answers about Kun me miekkailemme, me testaamme toinen toisemme refleksejä.
Why is it toinen toisemme here instead of just toistemme?
This is the formal or distributive way to express "each other's." The structure uses the word toinen twice: the first is always in the basic nominative form (toinen), and the second takes the required case plus a possessive suffix matching the subject. Here, we need the genitive to say "each other's" (reflexes), so it becomes toisen + -mme -> toisemme. In everyday spoken Finnish, you would usually just hear the plural toistemme.
How exactly is the word toisemme formed from toinen?
First, you put toinen into the genitive case because we want to say "each other's," which gives us toisen. Then, because the subject of the sentence is me (we), you add the matching first-person plural possessive suffix -mme. When adding a possessive suffix to a genitive word, the genitive -n is always dropped. Therefore, toisen + -mme becomes toisemme.
Why is refleksejä in the partitive case? Doesn't the genitive toisemme affect it?
The case of refleksejä is dictated entirely by the verb testata (to test). This is a partitive verb, meaning the thing being tested must be in the partitive case. Because there are multiple reflexes involved, it takes the partitive plural form (refleksejä). The genitive modifier toisemme just tells us whose reflexes they are and doesn't change the object case required by the verb.