“Oh, if only you could quicktalk! English is utterly inadequate, and slow. Like shouting poetry down a drainpipe.”
— Roberta Golding
Quicktalk is the name given to the language used by the Next between themselves, it is rooted in English but is super fast and dense and is not comprehensible to humans.
The Next children, being bright enough to invent their own language in order to express themselves, can do it naturally and the adults integrate what the younger ones invented so the quicktalk evolves and mutates all the time after each new addition.