Questions & Answers about Poika tunkeutui naapurin pihaan.
Why isn't there a possessive suffix on pihaan here, given the current lesson on 3rd-person possession?
The yard belongs to the neighbor (naapurin), not the subject of the sentence (the boy). The rule about using a possessive suffix to indicate "his own" only applies when the subject owns the thing. If the boy had intruded into his own yard, we would use the suffix: Poika tunkeutui pihaansa.
Why is pihaan in the illative case instead of a static location case?
The verb tunkeutua (to intrude, to force one's way into) inherently describes movement towards or into a place. Verbs expressing this kind of entering motion govern the illative case in Finnish, resulting in pihaan (into the yard) rather than the inessive pihassa (in the yard).
What is the base verb for tunkeutua and how does the -utua ending affect its meaning?
The base verb is tunkea, which means "to stuff," "to cram," or "to push" (like stuffing clothes into a bag). The -utua suffix is reflexive, meaning the action is directed at the subject itself. Instead of pushing something else, the boy is pushing himself into a space, which perfectly translates to intruding.
Does the word order of naapurin pihaan matter, or could it be reversed?
The word order is fixed here. In Finnish, a genitive modifier indicating possession (like naapurin) must come directly before the noun it modifies (pihaan). Saying pihaan naapurin would sound completely unnatural.