From Smith and Ama's account, it is a pretty simple language (like most creole languages) but has some interesting twists, like interrogatives going at the end of questions ("You did what?" "We are going where?") and surviving without infinitives (
Particularly useful - a section listing and explaining traditional foods, though it might not have killed the authors to provide the correct English names of the various types of fish and vegetables rather than just describing them. I was particularly amused that the samak yabis from Bor are named after the former political leader Abel Alier, while those from Nimule are named for his rival Lagu.
The book is also aimed at Juba Arabic speakers who want to improve their English. The very first sentence provided for them is the translation of the Juba Arabic Human azib-o lehaadi huwa worii le-oman sir: "They tortured him until he told them the secret". I winced when I saw that, but then realised that in fact it is illustrating subtleties of translation of the verb azibu, which has a rather less dramatic meaning in the sentence Kelib de gi-azib ana: "That dog is bothering me". I guess context is everything.