Kolísání délky v přejatých slovech

In native Czech words, vowel length is part of the word and rarely in doubt. Loanwords are different: they arrived through German, French, Latin and English at different times, and their length settled in different ways. Some are fixed short, some fixed long, and some have two accepted spellings. English gives no help here: Czech stresses the first syllable of every word, and length is independent of stress, so hotel has no long vowel despite English ho-TEL, while problém has one despite English PRO-blem.

Three groups

Group	Examples
short only	kultura, literatura, organizace, telefon, hotel, film
long only	móda, próza, túra, fáze, éra, kariéra, atmosféra, téma, systém, problém, banán
both accepted	benzin/benzín, citron/citrón, balkon/balkón, milion/milión, stadion/stadión, sezona/sezóna

The doublets are equal in the norm; the Internetová jazyková příručka lists both and you may pick either, as long as you are consistent within one text. Newer English loans tend to keep the length an English speaker hears: víkend, tým, líder, mítink, džíny.

The trap: length lost in derivation

Greek and Latin words in -ma and -ém lose their length in the international derivatives built on them:

• téma → tematický, tematika
• schéma → schematický
• systém → systematický
• problém → problematický, problematika

This is not a general rule of Czech. Ordinary Czech derivatives keep the length: móda → módní, fáze → fázový, banán → banánový, and even systém → systémový next to systematický. The split is by origin: when the derivative is itself an international word (-atický, -atika), it follows the international shape; when Czech built it with its own suffix, the length stays. Check the IJP when unsure.

A Slovak shadow

Kultúra, literatúra with a long ú are Slovak, not Czech. Learners who have spent time in Bratislava, or who read Slovak sources, carry them over; the Czech forms are short.

Typical slips

• Length kept in the international derivative: *tématický, *systématický → tematický, systematický (but systémový is correct).
• Slovak forms: *kultúra → kultura.
• Length guessed from English stress: *hotél → hotel; *problem → problém.