Questions & Answers about Koira nukkuu jalkani päällä.
Postpositions like päällä usually require the word before them to be in the genitive case. Why is it jalkani here instead of something like jalanni?
This is a very tricky rule! The postposition päällä (on top of) does require the genitive form, which for jalka (leg) is normally jalan. But when you add a possessive suffix like -ni (my), two things happen: the genitive -n completely disappears, and because that ending letter is gone, the "weak" consonant grade (jäl-) reverts back to its "strong" form (jalk-). So, the genitive word jalan plus -ni simply becomes jalkani.
Could I say minun jalkani päällä instead?
Yes, you can! However, in standard written Finnish, the minun (my) is optional because the -ni suffix already does the job of telling us whose leg it is. Including minun just adds a bit of emphasis.
How do we know the dog is on a "leg" and not a "foot"?
We actually don't! The Finnish word jalka is used for both the entire leg and the foot. You have to rely on the real-world context to know exactly where the dog has decided to sleep.
Why does nukkuu translate to "is sleeping" rather than "sleeps"?