There are five different vowels in Czech each of which can be pronounced either short or long. All the Czech vowels are pronounced fully and unflaggingly. Long vowels are exactly two times longer than their short equivalents. The length of vowels is completely independent of the stress. The stress is without exception always on the first syllable in all Czech words. Most long vowels are marked with the acute sign ´(čárka), long u is written with the circle (kroužek) ů except at the beginning of a word. The letters i and y are pronounced identically.

The háček sign above ě refers to the sound of the preceding consonant and does not change the pronunciation of the vowel e . After dentals d,t,n it indicates their pronunciation as ď, ť, ň (soft dentals), e.g.: děkuji (thank you), těžký (heavy, difficult), něco (something). After labials b, p, v, f, m it indicates the sound combination bj, pj, fj, mň, e.g. běhat (to run), pět (five), věda (science), město (town).

Dentals d,t and n are also pronounced as ď, ť and ň before i and í, e.g.: divadlo (theatre), ticho (silence), nikdo (nobody).

There are three diphthongs, produced by gliding from one simple vowel to another: ou, au, eu (o+u, a+u, e+u)