I always hated people who use multiple "etc" etc. is short for et cetera which means " and the rest" Saying it more than once makes no sense.
When I was younger people would say "for all intensive purposes" instead of "for all intents and purposes." This happens less now because the term is no longer common in either the correct or incorrect form.
People mixing up silicon and silicone sometimes leads to amusing sentences.
One I hear in the South mainly is using suit for suite.
Probably the most commonly misused word is "good" for "well" "Good" is an adjective and "well" is an adverb. Good is so often used as an adverb that it will soon be considered correct. In English there are already a lot of words that can be used as either an adjective or adverb like "fast" "clean" (also a verb), "late" and "most." The trend in English is toward the same word being used as either adverb or adjective.
There are several commonly misused words.
Lie and lay. Set and sit. To, too, and two. Your and you're. There, their, and they're. Than and then. Emigrate and immigrate. Principle and principal. Elicit and illicit. Climactic and climatic. Capital and capitol. Allusion and illusion. Affect and effect. Accept and except.
I do believe the MOST misused words are their, there, and they're. Not sure though, it's hard to say which is the most misused, as a lot of words are commonly misused.
disrespect: this may be a regional thing. I have heard some people put an ed at the end making it disrespected. Example: "He disrespected me." Is the speaker trying to say "he was direspectfull toward me" That is to say rude? OR are they trying to say "He did not respect me." that is to say "He has no regard for me, or thinks I am some sort of air head."
There, their and they're are commonly misused. Your and you're seem pretty common too. Many of the homonyms, the words that sound like each other but are spelled differently, are misspelled and misused.
I get confused with "bare" and "bear" and up end typing the word wrong in a sentence... Gotta agree with you, quite a few people mix the words "their" and "there" on here, it is a shocker.
That is what I thought, I don't think I use or misuse the other ones that much. If you look at my question above this one you can see where a user misused there for their.
I think it is, I myself have problems with that still, all the words that sound the same but have different meanings always are the ones that people get confused with.
I have problems with heart and hart, one is a body part the other is a deer, then there is strait, narrow like the straits of Florida, and straight, not crooked.
I bring this up because I use and misuse this all the time.
Their and there, and to and too