If I wanted to translate an imperative phrase: "Dad, eat quickly!" I can say
tenpo lili la mama o moku
However it seems a bit odd to me to put my vocative mama in the middle. It seems more natural to me that the vocative clause go towards the beginning of the phrase.
I might try
*mama o tenpo lili la moku
But I am not sure that this is right. It is my impression that o marks the verb, moku, in place of li rather than marking the noun, mama. And if the sentence were "Dad eats quickly", I'm quite sure
*mama li tenpo lili la moku
would not be grammatical.
Is there a common easily understood way to put the vocative noun at the front of the sentence? How do toki pona speakers usually structure imperative sentences with an adverbial phrase?