[Pulpmeister]

Baroque and ormulu are about as far away as you can get from Mies van der Rohe and Ikea. Metaphors of course.

Of course, when you're within quotes, writing dialogue, you can freely mess about with grammar as part of the technique of differentiating character through speech patterns.

And if you're writing in the first person, as in The Moon is a Harsh Mistress cited above, your character's grammar can be less than perfect too. Nevetheless, your intended meaning has to be clear to the reader, or else you're wasting your time--and the readers'. That's the function of grammar.

Heinlein, who had no problem writing correctly, created a complete Lunar dialect and wrote the entire book in it, a considerable feat; but nevetheless kept it clear and unambiguous throughout. He did that, not by torturing the language, but by the use of frequent non-English words and phrases, and by omitting many words which were not essential to meaning, eg, instead of the sentence "It was beautiful." he wrote "Was beautiful.". However, because the underlying grammar was right, the reader happily fills in the correct missing words unconsciously because there's never any doubt what the right words are.

If you are writing for a traditional publisher, an good editor will pick up errors and ambiguities and refer them back to the author for clarification. But if there are so many that the text is a mess, the whole lot comes back with a thanks, but no thanks, message.

But if you are self-publishing, whether on paper or digitally, all your errors are there for the reader to see--and judge.

I have one paperback book which I treasure because it's a wonderful how-not-to example. There are major typographical errors, grammatical bungles and spelling mistakes on almost every page (and I am not exaggerating). It was called "The Money Trail" and was published by a small press in the Channel Islands, quite likely the authors own imprint.