This may be old-fashioned, but I think "all right" is correct and not "alright" (which I see often in printed works.)
Similarly, I believe it should be "O.K." or "OK" and not "okay" in order to preserve its origin in the early 19th century as a deliberate, humorous misspelling of "all correct" as "oll korrect." (By the way, don't write stories set in medieval times and have people say "OK.")
I am also seeing "a couple of [whatever]" evolving into "a couple [whatever]" and I do not approve.
Some Golden Oldies, which I still see showing up in printed works by professional writers:
Mixing up "its" (belonging to it) with "it's" (it is.)
Getting the various tenses of "lie" and "lay" all mixed up.
Calling the things in your larynx "vocal chords" instead of "vocal cords."
Calling the thing that accompanies thunder "lightening" instead of "lightning."
Using "literally" to mean "metaphorically." I have heard a radio ad for a movie that said, with no touch of irony, "Action that literally explodes off the screen!"
Some new ones:
The phrase "comprised of" is ubiquitous, but is not correct, in my not-so-humble opinion. It should just be "comprises" (as in "The galaxy comprises many stars" and not "The galaxy is comprised of many stars.") This is so common that I try to avoid the word entirely and say something like "The galaxy is made up of many stars."
Using "share" when you just mean "said" or "told." ("The mayor shared her tax plans" may not actually be incorrect, but it grates on me. Use "The mayor outlined her tax plans" or some such.)
Calling any unusual experience "surreal." Blue flying giraffes spitting out melting watches are surreal; the car crash you witnessed was not.
Most of all, the grotesque overuse of "awesome" to react to everything. I have been in a restaurant, and the server's reaction to every item I ordered was that word.
