What puts you off a book immediately?

That's one of the most Jane Austen things I've ever read. Are you really not a fan?

I'm really not! But it's the content I object to, not the style of writing. I have to confess to converting dh too. He had always been pretty scornful of the fact I disliked Austen, in spite of my explaining why. Then he re-read one a while back and said "Actually, you know what, you're right!"

Oh one thing that annoys the tits off me is when a contrived "plot twist" is introduced that almost certainly would not have happened in real life - like leaving a Really Fucking Important Satchel or whatever behind a chair while spying on someone who wanted to Do You Wrong.
You just wouldn't - but without that contrived plot twist, the story is a lot less convoluted.
(Something like this happened in Kate Mosse's Labyrinth - I swear I honestly threw the book across the room when I read that and almost didn't finish it, I was so cross! Wish I hadn't bothered finishing it, either)

“The dragonmage Zz’gs’trymz’n strode forth, his sky-forged sword Hg’grin’dyr the Ever Silent at his side, to join battle with the foe”

That made me laugh!

First person.
Second person.
Switching POV all the time.

If any of the reviews on the cover call it "witty".
It invariably isn't.

Wise to don the hard hat. Did you ever wonder why it was so imperative for them to be husband-hunting?

Unfortunately, I don't find that understanding why it was imperative for them to find a husband makes it any more interesting to read about the process of them doing so.

I like police procedurals, but if the opening section is in italics, from either the victim or the perpetrator's point of view, with identifying details carefully concealed, I close the book and do not go any further.

• Names including a lot of consonants and apostrophes, eg Zz’gs’trymz’n.

• High-falutin’ bollocks like “The dragonmage Zz’gs’trymz’n strode forth, his sky-forged sword Hg’grin’dyr the Ever Silent at his side, to join battle with the foe”.

• Historical fiction where the author gets details wrong – looking at you, tight-laced corsets (most weren’t) and women running down the street not wearing hats and gloves.

• Authors making up swear words. (You've imported names and offensive gestures from our English-speaking world: why make up some new word and use it exclusively when we have many, many excellent words that would do the job, especially as context indicates that the well-known and often-used “fuck” is what you mean?)

• Fantasy books that are not internally consistent. If you mention that magic can’t, for example, create fire, magic should not create fire later in the book/series.

• Books set in English towns (I’m sure this applies to other countries) that are obviously written by an American whose closest contact with said town is a cursory glance at Google Earth.
• Books set in England (again, I’m sure this applies to other countries) that are obviously written by an American and use American vocabulary – it’s a car park not a parking lot, a pavement not a sidewalk.

• Stilted vocabulary. This is supposed to be a modern 16 year old girl speaking to her boyfriend: "The landscape had changed. The paths I remembered were no longer there. The hills and valleys almost seemed to have been reordered." "I became excited and he looked more than a little sad... Of course, I didn't heed his warnings".

• Hard science fiction that's just bang-bang-shoot-'em-up set in space with a little spaceship maintenance for the people who like tinkering under the hood of the car.

"If you only read one book this year make sure it's this one". No.

A map
Too many characters on the back cover

Another off-putting thing - the discovery of a diary or a letter revealing the mysterious past of Gt Aunt Gwendoline, which could shake the foundations of the whole family - YAWN. There are about a million variations on this theme - and none of them any good.

Heroine with a hobby-type business who can still afford a delightful sounding house.

Heroine whose flaw is that she is 'too skinny' (but not through illness or ED) so she can't get a bloke.

Diary entries. I find they very rarely ring true. Put me right off "The Thursday Murder Club". Also first person narrators who often seem to write "ah, but I'm getting ahead of myself" - seems to be just a lazy way of getting background information in and then abruptly stopping because you don't know how to introduce the main story.

Definitely overuse of similes- just too try hard and irritating.

I feel robbed of the indulgence of the story when the writer tries to interact with you as the reader. Roddy Doyle did it in either Smile, or The Guts maybe - I mean when suddenly the narrative changes to something like…

“And what happened to our protagonist, dear reader? I realised I had only one real choice with how this was going to end, I’d like to have given him an easier outcome, but come in! Let’s be realistic, you know there is only one way this ends…” etc etc

(Hope I’m explaining myself)

I need the author to remain invisible.

Oh and I skip too much description that has nothing to do with the plot. I'm not interested in the creaminess of the coffee or the way the waves roll and crash. A sentence or two will suffice.

I also get distracted when an author sets the story in a known place and spends too much time mentioning places and parks. We get it, you're from Camberwell. On to the killer

When I was younger I HATED reading books written in the first person, that I couldn't read them. Now I'm so used to it that I find it strange if it isn't written that way!

I'm a bit fed up with the historic present. H. Mantel did it well but it now seems ubiquitous and I'm weary of it (looking at you 'Hamnet'.)
Hate it when the reader's made to work too hard (see lack of punctuation which generally equals lack of sense and clear narrative). Also books like 'Lincon in the Bardo): wtf!

Poems or songs in the middle of a chapter, I always skip them, I hate poetry

Not too keen on books that switch perspectives to new characters throughout, like Girl, Woman, Other or David Mitchell's Cloud Atlas. So one chapter will be from one POV, then the next someone else entirely.

Also don't like it when we personally encounter real historical figures in novels which aren't about them.