Datapoint Nigerian Pidgin/Vocative markers
A number of phrase/clause final markers such as o, ba, sha, kwa, naw, etc. occur at an extremely high frequency. O may follow a form of address as part of a vocative expression, but the use of o is not restricted to a purely vocative function.
Values 
Optional vocative marker following noun
- Example 17-187:
-
Àdé (o), haw bò̱di?ÀdéÀdé(o),(voc)hawhowbò̱di?bodyHey Àdé, how are you?
Source: Faraclas 1996: 27
- Confidence:
- Very certain