On 'bad' English and what it reveals

The dwarves of the Land, known here as Duergars, speak Solomon Island Pidgin. I'm still not sure if I've got a decent reason why it should be that in the terms of the book, but that it is some sort of pidgin is because it makes them look dim.
They aren't, but that's the way the world tends to think, isn't it?
They are actually modelled on Philipinos, who do tend to be smaller than Europeans and who also tend to be cheerful, polite, hard-working folk who make things work. Especially here in the UAE.
They speak English with a very distinctive accent, which is a thing that marks you. Geordie is now a popular accent in the UK, from what I've read, but I still remember when Geordies were described as speaking like Scotsmen with their heads kicked in. When I went off to do teacher training in Huddersfied Poly, I was told by someone (who thought it one hell of a laugh) that Geordies were the only ones in the country to do an oral English exam. My copy of Billy Elliott is subtitled in English - possibly for the benefit of Americans, who would have real problems - but as likely for the rest of the English, who were just as much in need of translation.
GB Shaw wrote Pygmalion to point out how much accents propped up the class system in the UK and how easily a person gets slotted into a position in the pecking order as soon as they open their mouth. So some things have changed and that is good, but it's still the idea that 'bad' English equals stupid.
The Duergars speak Solomon Island pidgin for my two reasons that I know it and that it sets up expectations that I can later upset. I spent four years in the Solomons, teaching in secondary schools there. It's a topic for another post, but I didn't see any evidence that the kids I taught there were thicker than any others I've ever taught - they just hadn't seen some things or been taught them before.

Again, as with Phoebe's speech, it's something that puts some people off. They don't understand what the Duergas are saying and start to lose interest because of that. For myself, I can't think of this as a big problem. I've made sure that what they say in Pidgin is both not that important and is comprehensible from context or translation. Later, when  a Duergar needs to say something of importance to the story, he speaks in English. There's a trick to that which I won't go into yet.
For now think on the fact that the servants in this story speak 'broken English' and think why someone would do that.

The harder one to write

I've never had any experience of being a girl on the brink of her first period, or any other kind of girl if it comes to that. So Phoebe is difficult to write as so much of what is going on inside her head is guessed at. And Phoebe is difficult as she speaks in a teenspeak that hasn't been invented by real teens yet, so she is hard for many people to read. Some of the comments I've had back have identified her as a major headache. Others, mind, have enjoyed her perspective and have liked the idea of the teenspeak. It takes all sorts.
A few commenters didn't like the introduction of Tony Blair (though many have loved the idea of him being in jail).
He's there partly because burning him at the stake would contribute to global warming and because he gives a (subtle, I hope) clue as to the time frame of the story. This can't be the far future, as Blair is still alive, though it must either be the future or a different time line in which history has turned out better than we managed it in this one. Phobe says she found out about him when she was eight and she must be around 12 to be on the verge of a first period.
Her teenspeak is built up of parts that should be recognisable to any reader: tres, tres ok being an example; parts that will only be recognisable to a Japanese speaker: mecha, cho, yada; and parts that I made up as I went along. On the grounds that George Harrison claimed 'grotty' as being derived from 'grotesque', I decided that 'gruse' could easily come from 'grusome'.
It isn't nearly as hard to get your head around as either the teenspeak of Clockwork Orange, or Bascule the Rascal's semi-phonetic writing in Feersum Endjinn, or Ridley Walker's purely phonetic script in the book of the same name. They are all bloody difficult when first encountered, though you do get into them. I reckoned I'd be adding a bit of interest with Phoebe's and still not going so far into the linguistic twilight zones that others have entered.
There's one bit of questionable plotting when Phobe realises that she is Malaika. She knows it and recognises the face. Adam, you'll find out later, doesn't recognise the faces of any of the people he sees, though he knows they must be famous. In my own mind I sort this out by thinking that he is supposed to be new, so the computer has suppressed his memories so  as to make the whole experience more 'real' for him. Phoebe couldn't operate on this basis, as Malaika has to know who she is talking to, so the suppression hasn't been performed on her. This is never made much of in the rest of the book, but will be in book two.
Had Phobe been put into the body of a Seeker, her memories of the people would have been similarly suppressed. And so might her memories of the stories. Neither she nor Adam question the fact that she knows what is going on here, so we can guess that no one has told them things will be otherwise. Later, Adam decides that her knowing the plot might be a design feature that would allow anyone coming into the Land to cheat, but it is actually a mistake and the reason why the prologue refers to the moment of her character ID changing as being of so much import.