Well most threads are kind of light hearted fun, that's what I meant
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The only thing you can do is practice. Read as much as you can, write as much as you can. There's a forum on here where people post excerpts of things they've written, that might help as people can give you advice. Most people's grammar is poor. Mine certainly isn't perfect, but everything I write then goes to an editor to tighten it up anyway so it doesn't really matter as long as it's fairly accurate.
I wrote my first book in 2012 as part of NaNoWriMo (Google if you don't know what that is) and self published it. It was on sale for about 8 months but only ever sold just over 1,000 copies which is nothing in comparison to established authors. Although it did make enough money to cover the time I spent writing it so that's okay. I pulled it from sale because a client of mine said she could put me in touch with her agent - which she did - so we're now preparing for it to be published properly. And that takes A LOT of work. It's slow going because I'm busy with other things, but I'm fairly positive about it.
I also have 4 other books which are written but not edited at all. Those are definitely on a back burner until the first one is out, though.
I struggle with actually writing books because obviously I don't get paid for them there and then, so I have to make sure I have enough paid work to pay the bills.
I do have a number of eBooks on Amazon which bring in royalties but they're not selling that well, it's only really enough for a decent meal out each month to be fair. But it's not bad as I got an upfront fee for the eBooks so I was paid anyway.