"The duck is on the elephant."
Translation:Ördek filin üzerinde.
Thank you for all the answers. So, that poses the question: how do you differentiate in Turkish between "There is a bird on (top of) the elephant" and "There is a bird above the elephant"? And let's assume there are birds both on the elephant and above it. How do you point them out differently? Thanks.
normally we wouldn't differentiate. If we really want to (as in your case, where there are two), you can say "yukarı taraftaki" for the one that's above. So
"filin üstündeki kuş, yukarı tarafındaki kuştan daha küçük": "The bird on the elephant is smaller than the one above it."
But this is really when you just want to differentiate. Normally it is not really common to say "filin yukarı tarafındaki kuş", we would also just say üstünde or üzerinde for above.
Consider an English sentence like "The duck is on the elephant's back" -- there you can see that "elephant's" is genitive because the back "belongs to" the elephant.
Most Turkish location words work similarly; "üzeri" is a noun meaning something like "top", and so the duck is "on the elephant's top": filin (elephant's) üzerinde (on-it's-top).
Similarly, something like "between the books" (kitapların arasında) is in Turkish "at the books' area-between", and "in front of the house" (evin önünde) is "at the house's area-in-front, at the house's front" -- all with genitive.
I think "üzeri" already contains what your are looking for. "Filin üzeri" is the elephant's top, kind of. So, saying "üzerisi" would be doubling the possessive ending. In other words, "üzeri" already contains the possessive suffix. The optional "s" is only there in some words, depending on the ending of the root word. For example, it would be there with the word "bahçe" - "garden":
I: bahçe-m - my garden
You: bahçe-n - your garden
He/She: bahçe-si - his/her garden
And it is not there with the word "el" - "hand":
I: el-im - my hand
You: el-in - your hand
He/She: el-i - his/her hand
That is how "üzerinde" works, as well, kind of.
And a funny thing is, when you add a further suffix, "-de", the singular second and third person forms may end up the same:
2nd person: el-in-de - in your hand
3rd person: el-i-n-de - in his/her hand - The "n" here is a buffer sound between the two suffixes.
Same way with "üzerinde":
2nd: üzerin-de - on top of you
3rd: üzeri-n-de - on top of him/her/it
That's why, if there is a possibility of confusion, they will add the personal pronouns:
"senin üzerinde" - on top of you
"onun üzerinde" - on top of him/her/it.
Experts, please correct me if I am wrong.
You know what, maybe my explanation is not totally correct. Maybe, indeed, the base noun is "üzeri" and, logically, it should be "üzerisinde".
After all, we have "içeri" and "içerisi" for "the inside of" sg. So why not "üzerisi", following the same pattern?
But it is not "üzerisi". It is "üzeri". Let's just call it an irregular case. The reason for it could be the natural simplification of languages. There was probably no need for distinguishing "üzeri" and "üzerisi", ie. there was no use for "üzeri" to be meaning anything other than "the top of sg". So "üzeri" assumed the role that would have belonged to the more complicated "üzerisi", rendering it unnecessary and practically nonexistent. Something like that.
This is not unusual with languages. Something should logically and regularly be expressed in a more complicated way, but frequently there is a kind of "shortcut".