-on/-en/-ön/-n

The superessive case is one of the most common locative cases in Hungarian. Its usage falls into several main categories:

• Physical Location: Used for objects on a surface (e.g., az asztalon - on the table).
• Cities and Islands: Many Hungarian cities (like Budapest or Szeged) use the superessive. For foreign cities, the default is -ban/-ben (e.g., Londonban, Párizsban), except those ending in -vár (e.g., Szentpéterváron). Note that cities in neighboring countries with traditional Hungarian names generally take the superessive, just like domestic cities (e.g., Kolozsváron, Szabadkán). Notable Hungarian exceptions like Debrecen, Eger, Győr, and Sopron use -ban/-ben, while Pécs takes the superessive (Pécsen) or the archaic locative (Pécsett). Geographic islands and many island nations take the superessive (e.g., Margitszigeten). However, island nations treated primarily as countries (especially those ending in -ország like Írországban, or places like Japánban and Kubában) take the inessive.
• Institutions and Events: Used for specific public institutions (e.g., a postán - at the post office, az egyetemen - at the university) and events or occasions (e.g., az esküvőn - at the wedding).
• Public Transport: Used for most vehicles you 'board' like buses, trains, planes, or bicycles (e.g., a buszon). Note that cars use -ban/-ben.
• Communication and Media: Used for communication devices and platforms (e.g., telefonon - on the phone, az interneten - on the internet).
• Musical Instruments: Used when talking about playing an instrument (e.g., zongorán játszik - plays the piano).
• Time Expressions: Used for days of the week (e.g., hétfőn), except for Sunday (vasárnap), which takes no suffix. For seasons, it is only used for nyáron (in summer) and télen (in winter). Be careful: spring and autumn use the instrumental case instead (tavasszal, ősszel).
• Dates: When expressing 'on' a specific date, the superessive is attached to a possessive suffix, resulting in endings like -án/-én (e.g., tizedikén - on the 10th).

Suffix Selection:
1. -on: For back-vowel words (e.g., asztalon).
2. -en: For front-unrounded vowel words (e.g., széken).
3. -ön: For front-rounded vowel words (e.g., bőröndön).
4. -n: For words ending in a vowel. Note that final -a and -e must lengthen (e.g., almán).

Important Note: While English uses 'in' for cities, Hungarian distinguishes between 'inside a container/room' (-ban/-ben) and 'at a location' like a city or a surface.