When u-/o- nouns are used in the vocative, in other words when you call a person, address a person directly, or give a command to a person (or persons), the class prefix of that noun falls away:
- Mama! (Mother!) instead of umama
- Gogo! (Grandmother!) instead of ugogo
- Hamba malume! (Go, uncle!)
- Sala kahle, baba! (Goodbye father!)
When addressing more than one person, use the plural imperative together with the vocative prefix bo- :
- Gijimani kakhulu, boSipho! (Run fast, Sipho and those with you!)
- Hambani kahle, bomalume! (Go well, Uncles / Uncle and company!)
The vocative prefix bo- is commonly left out because the plural imperative suffix ni- already indicates the presence of more than one person:
- Yidlani kamnandi, malume! (Enjoy your meal, Uncle and those with you
When a person in any other class is addressed in this way, the initial vowel of the class prefix, i.e. the preprefix, falls away:
- Dlalani kamnandi, bafana! (Enjoy your playing, boys!)
- Woza masinya, ndoda! (Come quickly, man!)