Vocative
Ahoj, Petře! Dobrý den, pane Nováku!
In short
When you talk to someone, their name changes a little. For women, -a becomes -o. For men you usually add -e, but after k or h it's -u, and after soft letters like š or j it's -i.
- Ahoj, Jano!Jana
- Ahoj, Martine!Martin
- Dobrý den, pane Nováku!pan Novák
- Ahoj, Tomáši!Tomáš
Full explanation
This is the case you use when you're speaking directly to someone: saying hello, asking a question, starting an email. Czechs really do use it, so Ahoj, Petr! sounds a bit off. It should be Ahoj, Petře!
Men's names and words
- Most just add -e: Martin → Martine, pan → pane, doktor → doktore
- If there's a consonant before a final r, it becomes -ře: Petr → Petře
- After k, h, ch you add -u: Novák → Nováku, kluk → kluku
- After soft letters (š, ž, č, ř, j, c) you add -i: Tomáš → Tomáši, Ondřej → Ondřeji
- -ec turns into -če: otec → otče
- Sometimes an e drops out: Pavel → Pavle, Marek → Marku
- Men's names ending in -a work like women's: Honza → Honzo
Women's names and words
- -a becomes -o: Jana → Jano, Eva → Evo
- Names ending in -e and surnames in -ová stay as they are: Marie, paní Nováková
When you're being formal, both words change: pan doktor → pane doktore. The one exception is paní, which never changes.