Using "their," which is a plural word, as a singular pronoun with a singular verb. I know that English does not have a gender-neutral singular pronoun, but so what. You sound stupid when you mix a plural subject with a singular verb.
Calling people "that" instead of "which." If you think about it, you'll realize that it's an insult to people. I'm not a "that."
"Try and [verb]" instead of "try to [verb]." So stupid.
Run-on sentences.
Clauses that pose as sentences. Probably the most common form of this error is a declarative sentence that begins with the word "which."
One that has always bothered me, it may not even be incorrect technically but i hate it anyway, is when people say " I texted you earlier" or some other variation. Surely it is "I text you".
According to google answers, the online version of the Oxford English Dictionary, there has been a verb "text" since the 1500s, with a past tense of "texted" or "tex'd." The current meaning of "to send a text message" was accepted by the OED in its draft additions of June 2004, and include the example of "texted."
In your example, wouldn't it be more correct to write "I've texted you earlier"?
I've no problem with slips and graofftopicr mistakes from individuals (I'm sure I do my own).
But I hate it when companies do it. It seems that loads of people have started design businesses (flyers, banners etc) because of the easy access to software but without even a basic knowledge of English.
There's a banner in Leeds at the site of where a young girl was run down and killed.
Part of it reads "You would of been 14 this year". "Would of"!?!?! "Would have" my dears.
And nobody spotted it before printing a banner and putting it up? Not the designer, not the printer, not the parenst/relatives!?! Amazing.
And I recently got a flyer for a toddler group that does nature trips that used "your" instead of "you're".
If you can't type and proof read basic English then you have no business producing any deisgn without passing it under the nose of someone that does.
Not sure whether this counts but i absolutely despise it when people write in annoying text talk...
e.g.
Hey wut u 2? U ok? Yh i jus been 2 town, wil c u l8tr 2day
God even typing that was more effort than running a marathon. When i see anyone type like that, i just instantly tell myself to never talk to this person in my life again... until they reform back to what a human is.
If they have slight annoying leet talk in them such as
Hey what u up to? U ok? Yh i jus been to town, will c u later today.
I can bear that, although i still tell the person to spell properly, if they dont then i just wont reply until they start spelling words correctly.
What i dont mind, is replacing the you's with u's, but it still bugs me.
apostrophes i can understand, spelling mistakes i understand if you cant spell, i mean i suck at spelling too! haha!