The ablative case: -den / -dan / -ten / -tan
The ablative marks where something comes FROM: evden (from home), Ankara'dan (from Ankara). Four-way harmony for the vowel (e front, a back) and a consonant alternation: after voiceless consonants (p, t, k, ç, f, s, ş, h) the suffix begins with t instead of d — kitaptan (from the book), Türk'ten (from a Turk). The ablative also serves comparisons (-den daha, 'more than'), partitives ('one OF the books'), and idiomatic causes ('from the cold').
Vowel harmony — two-way for the vowel
Like the dative, the ablative vowel is two-way: e after front-vowel stems (e, i, ö, ü) and a after back-vowel stems (a, ı, o, u). ev → evden (from home). okul → okuldan (from school). göz → gözden. kapı → kapıdan (from the door). After a vowel, no buffer is needed because the suffix already starts with a consonant: araba → arabadan.
The d / t alternation
Turkish writes consonant assimilation in the spelling: after a voiceless consonant (p, t, k, ç, f, s, ş, h) the suffix's initial d becomes t. So: kitap → kitaptan (from the book), dolap → dolaptan, çocuk → çocuktan, iş → işten (from work), Ahmet → Ahmet'ten, Türk → Türk'ten. Memorize the voiceless set as the mnemonic 'fıstıkçı şahap' (a Turkish phrase containing all eight). After voiced consonants and vowels, d stays: ev → evden, araba → arabadan, göz → gözden.
Personal pronouns
ben → benden (from me), sen → senden, o → ondan, biz → bizden, siz → sizden, onlar → onlardan. Used naturally with gelmek, almak, istemek: Senden alıyorum = I'm taking (it) from you. Ondan istiyorum = I'm asking (for it) from him.
The 'where from?' question
Nereden? = From where? — nere- + -den. Nerelisin? is a related idiom: literally 'where-from-are-you?', meaning 'where are you from?' (about origin/nationality). Common dialogue: —Nerelisin? —Türkiye'denim. / Türk'üm. = Where are you from? — I'm from Turkey / I'm Turkish.
Comparison: -den daha
Turkish makes comparisons with the ablative + daha (more): Ali Ayşe'den daha uzun = Ali is taller than Ayşe (literally 'Ali than-Ayşe more tall'). Bu kitap o kitaptan daha güzel = This book is more beautiful than that book. Often daha is dropped in casual speech: Ali Ayşe'den uzun still means 'Ali is taller than Ayşe'. The thing being compared TO gets the ablative.
