I know the language only has 'two' prepositions (though there seems to be a some dispute to that). Regardless, the two prepositions 'long' and 'bilong' seem to be quite broad in definition.
I do wonder though how this works in practice. Note that I've been having a hard time finding information about the language other than 'introductory' grammars. Like, has there been any major publications or translations in the language? Is the language so context sensitive that it doesn't work when written? Can you explain complex thoughts in it? Like, can you debate philosophy or science or what not. Does anyone speak nothing but Tok Pisin?
I'm asking this because there's lots of auxlangs out there that try to be minimalistic, with some rediculing languages that have more than Tok Pisin.
Of course, I know such a minimal list isn't always what it seems. Like Tagalog, which just marks everything on the verb. I think the Polynesian languages do this too to an extent. Essentially, the verb takes markings (well, I think the Polynesian languages use particles, but not like that's relevant) that give more precise meanings to the prepositions. For example, they only have one generic preposition for locations, they use affixes/particles to disambiguate whether the one locative preposition means 'in, on, outside of, etc...' But to my knowledge Tok Pisin doesn't do this. You just have to rely on context on common sense it seems to figure out the intended meaning.