Questions & Answers about Nuori poika ajaa kaupunkiin mopolla.
In English, he rides a moped, making it the direct object. Why isn't mopo in an object case like the partitive or genitive here?
In Finnish, you don't typically "drive a vehicle" as a direct object when traveling to a destination. Instead, you go somewhere by means of that vehicle. The adessive ending -lla in mopolla tells us the moped is the instrument or means of transport being used, translating more literally to "by moped".
Can I use the verb ajaa for riding a bicycle or a horse, too?
Yes for a bike, but no for a horse! The verb ajaa is used for operating machines or vehicles. You can say ajaa pyörällä (to ride a bike) or ajaa autolla (to drive a car). To ride an animal, you must use the specific verb ratsastaa (e.g., ratsastaa hevosella).
Why is kaupunkiin in the illative ("into") case instead of the allative ("onto") case?
The illative case ending -iin is used here because the boy is physically traveling into the city limits from outside of it. If you used the allative case kaupungille, it carries a slightly different, more social meaning—it implies going "out on the town" to the city center to hang out, shop, or run errands.
Adding -lla closes the final syllable. Why doesn't the p in mopo change to a v due to consonant gradation?