I suppose it is too bad that we lost whither and whence. These things would be easier to translate explicitly, if we still had them.
If enough people started reusing these archaic words, we could bring them back and I hope we do :)
This "genitive case" lesson is yet to come, right? Or I may be missing on something?
It changes because of the vowel coming after it. I think "gitmek" ("to go") is one of that small group of verbs that people started using before they invented grammar. So it's somewhat irregular; most languages have those. Gitmek and etmek are the two most important verbs that follow this pattern. Gitmek >> gidiyor; etmek >> ediyor. But this is definitely not the rule. Bitmek, itmek, tutmak, yatmak - just a few examples; the verb stems of these do not change from t to d. With other types of words, nouns, etc., this type of consonant change is wide-spread. There are simple rules describing the process. With verb stems, however, it is very rare.
It is remarkable how similar Turkish is to Japanese, despite being a continent apart ! They have 'ni' for dative and 'de' for location ! Eerily similar to Turkish 'de' minus the vowel harmony...
It is not really remarkable, because Turks are originally from the area close and around Mongolia, north of China, which is not too far from Japan. And thus, Turkish is classified as an Asian language.
I do understand that nerede has to be in the dative case, (maybe i missed it) but i only remember bana sana ona etc. How does it work with words like nerede?
The dative case ending is -(y)E (small vowel harmony).
For "where, from where, to where", the case endings get tacked onto a stem "nere".
So you have nerede "where? (locative)", nereye "to where? (dative)", and nereden "from where? (ablative)".
Similarly with "burada, buraya, buradan", "şurada, şuraya, şuradan", and "orada, oraya, oradan" for "(to/from) here" and "(to/from) there".
"nerede" implies a static location (in/at what place).
"nereye" implies motion "to" somewhere. (to what place)
And, I've realized something.
Nerede, -de is the locative suffix, right?
Then, I'm sure Nereden is also exist. :D