The rule that runs the language
Vowel harmony
Suffixes come in two or three outfits. The last classifying vowel of the word chooses the outfit. Get this, and cases stop looking random.
Harmony bench
Type a word
Last classifying vowel wins. i/í stay out of the fight unless they are alone.
Front unrounded — endings like -ben, -ek, -hez
vowels u · a · e
- inessive-ben
- dative-nek
- allative-hez
- plural-ek
- 1sg indef.-ek
The three camps
- Back — a á o ó u ú. Deep in the mouth. ház, három, autó
- Front unrounded — e é. ember, kér, szép
- Front rounded — ö ő ü ű. Purse. könyv, ül, tűz
- Neutral — i í sit out. Alone they act back: írok, not írek. In segít the e decides (front).
Two-fold vs three-fold
Two-fold endings only care about back vs front: -ban/-ben, -nak/-nek, -val/-vel. Rounded and unrounded front collapse together.
Three-fold endings split the front camp: látok, szeretek, ülök. Same split on -hoz/-hez/-höz and -on/-en/-ön.
Mixed stems
Last classifying vowel usually wins: béka (frog) takes back endings because of the a. kettő is rounded because of ő. Loans sometimes freeze an unexpected suffix — learn those as words, not as rebellions.