Bad Grammar in The Great Gatsby?

Question

I'm sure many here have encountered a common error in written English, whereby 'have' is substituted by 'of'; 'should of', 'would of', 'could of', etc. It's my understanding that this is always grammatically incorrect, and derives from when people contract 'have' to 've' ('should've', etc.) which sounds a bit like 'of'. However, there are a couple of instances of this error appearing in books I've read, most recently The Great Gatsby.

On page 32 of my edition (Penguin Classics, 2010), Myrtle says:

"I had a woman up here last week to look at my feet, and when she gave me the bill you'd of thought she had my appendicitus out."

Likewise, on page 74, Wolfshiem says:

"It was four o'clock in the morning then, and if we'd of raised the blinds we'd of seen daylight."

To my mind, these instances should use 'have' instead of 'of'; "you'd have thought...", "if we'd have raised...we'd have seen...". So either;

1. I'm wrong about this being bad grammar.
2. It's a grammatical use which was acceptable when Fitzgerald was writing but no longer (though that doesn't explain the same error in Terry Pratchett's and Neil Gaiman's Good Omens).
3. It's an error with my copy.
4. It's a deliberate error to indicate a 'lower' use of language by these specific characters to contrast with the likes of Nick, Gatsby, etc, like how Myrtle says 'appendicitus' when she means either 'appendicitis' or 'appendix', or Wolfshiem calling Oxford 'Oggsford'. (This might also explain the use in Good Omens.) If this is the case, it's quite subtle for what is supposed to be dialogue.

Answer 1

It's "deliberate" bad grammar to portray uneducated people who are not part of the elite. So their using "would of" in place of "would have" is part of the "characterization" of such people. At some level, they don't really belong in a novel with people like Nick, Daisy, Jordan, or even Gatsby. Except that they were "hangers on," Myrtle as the mistress of Tom Buchanan, Wolfshiem as the mentor to Gatsby. Note that even the elite can develop deep dependencies on people far outside their circle.

Wolfshiem was a smart man, but he was "street smart" rather than book smart. Upon meeting Gatsby, the older man knew at least three things about the younger: 1) Gatsby lacked his own street smarts, and could thereby be controlled. 2) Gatsby "caught on" quickly, and in Wolfshiem's fractured English (he was an immigrant), "I knew that I could use him good." 3) Gatsby, besides being a "WASP," had the "polish" that Wolfshiem knew he lacked. While he hadn't exactly graduated from "Oggsford," he had attended "college" for five months, and it showed. And not just any college, but one that was then regarded as one of the five best in the world (alongside Harvard, Yale, Princeton, and Cambridge).

Answer 2

It's possibility 4. These are dialog, and they are undoubtedly meant to convey a pronunciation of have without the /h/. You could also spell this pronunciation: if we'd've raised the blinds we'd've seen daylight.

Note that there are other mistakes in this dialog. The second 'd in the second sentence is also incorrect grammar (of a form that is quite common among Americans now, and presumably was not unknown, but which probably was more noticeable as wrong, when Fitzgerald wrote the novel).