I see people writing things like, “That could of been me.” when I believe they mean “That could’ve been me” which really means, “That could have been me.”
The “have” in the contraction sounds like “of,” in terms of speech recognition, I suppose, but does using the word “of” in place of “have” make sense in terms of standard usage?
It seems not just poor usage to me, but an actual grammar error.
Yes, it’s a grammar error. “Have” is a past-tense verb, and “of” is a preposition; they are not interchangeable. If you remove the modal verb “could”, you end with with “that has been me”. You can see that “has” is a different form of “have”, but “of” has no place here.
It’s a plain error, although somewhat more common in British English than in American English.
IMHO whether it’s a grammar error or a spelling error depends on what words the writer thought she was using.
I don’t see how it could be considered a spelling error. No one could misspell “have” as “of”, or even “'ve” as “of”. The writer clearly thinks “of” is the correct word here.
The question is, does it count as a spelling error if you replace a word with its homonym, as in “I crashed are car because I didn’t step on the breaks in time”?
It’s common enough in American English, in any event.
Nm
I consider it both a grammar and spelling error. It’s clearly an incorrect transcription of the contraction 've. When typing fast, I’ll do the same thing with other homonyms quite often. I guess it depends on what you consider a spelling error. I don’t really think intentionality has anything to do with it. I’m pretty sure somewhere along the line I’ve written “could of” instead of “could’ve” and I clearly know the latter is correct.
It’s just someone writing the word that they hear rather than the correct one. The same problem that makes people write ‘except’ instead of ‘accept’ and ‘effect’ when it should be ‘affect’.
Linguistic laziness.
There’s research as far back as 1997 suggesting that " 've " has been reanalyzed as “of” for a lot of people. I know I don’t have a problem with reducing “a bunch of grapes” to “a buncha grapes” or “I should have gone” to “I shoulda gone” but I am definitely not on board with “the kidsa told us” instead of “The kids have told us” suggesting that the “a” affix there is actually substituting for of, not have or 've. Fascinating.
I see that error a lot. ^
IMO it’s the result of the continuing dumbing down of the public. I don’t know the actual rules for grammar any more, but it’s like pornography – I know bad grammar when I see it.
Another one I’ve seen in recent years that annoys me is interchanging “then” and “than.”
“This one is smaller then that one.”
Some of the rules for English grammar are pretty complex. I suspect many people are like you and me, i.e. we know how to use the words but we can’t readily articulate why a particular way is correct or incorrect. I didn’t know what a modal verb was until I started searching the web for “could have/could of”. I know how to correctly use “have” and “has” but I couldn’t explain the difference to you. I learned the word preterite as I started exploring that difference.
My wife speaks English as a second language, so I find myself searching the web from time to time to be able to explain these kinds of details to her. Present-perfect, pluperfect, past perfect progressive, all that sort of stuff. I remember it long enough to explain it to her, and then it falls out of my brain again. 
The simple answer is this: The reason people can’t write is because they don’t read.
I hated English when I was in school (class of '68). As you said, it was very complex and also boring to me. We had to take and pass English all the way through 12th grade or we couldn’t graduate.
As for second languages: I’ve been online since 1994, and I’ve run into a few people who seemed to write quite well yet apologized for a couple of very minor errors, saying that English was not their native language. Heh – I told them that they write much better than a lot of Americans.
That certainly has a lot to do with it. The easiest way to learn proper grammar is to read stuff that is properly written – and material like that is not so common as it used to be.
With the auto-fill (?) or whatever it’s called (the device thinks it knows what word you want) some people end up posting pure jibberish. You have to read it several times to even know what they’re talking about. Why people post that crap without proofreading it first is beyond me. The writers aren’t necessarily stupid, but they sure appear to be.
This is a problem on some forums where it is considered bad manners at the very least to correct anyone’s spelling or grammar. I have been accused of being a ‘grammar nazi’ after correcting an illiterate post.
As Dr Johnson cheerfully acknowledged when taxed by a lady about an error in his magisterial Dictionary, “Ignorance, Madam, pure ignorance.”
And I believe it should always be corrected on this board. Firstly because allowing it to stand makes the place look bad, and secondly because it’s the board’s duty to fight ignorance wherever it appears.
For me it stands out like their/there/they’re, and you’re/your, used interchangeably. I’m not going to judge you as a person, but I will judge you education as clearly and significantly inadequate. And I will definitely feel truly sorry for you, having to go through life with a habit that screams ‘not so smart maybe’, to all and sundry whilst you continue merrily along in blissful ignorance. Especially if you’re otherwise intelligent, and seemingly well spoken.
How does a person get through middle/high school or any post secondary education without correcting these basic errors, in a language that is their first tongue?
But does anyone correct others on this front? Your work colleagues, or spouses, or siblings? I can’t bring myself to, to be honest. I love and respect this person and don’t want to offend them, so I say nothing at all. Just feel increasingly embarrassed for them, and then wonder what I myself do that makes others similarly cringe.
I know. Its that bad.
I’ve occasionally done it on this site, when the the misuse was so persistent that it grated on me (e.g. the repeated use of the word “breaks” in a discussion about slowing a car down). IRL, etiquette prevails and I don’t correct someone else’s writing unless I’ve been invited to do so, or I’m reviewing a group effort in which the quality of the final document reflects (at least on part) on my reputation.