hte
At least I have autocorrect.
When I’m in a command shell, I invariably type “pyhton”. So frustrating.
Another one who hangs onto that shift key for a fraction of a second too long. Outlook used to correct it for me, but Gmail (our company email provider now) does not. I manually correct a whole lot of closing “THanks”.
I’m another one who hold down the shift key a tad too long.
But since I had a small stroke two years ago, my typing has gotten sloppy. I have to slow down from the speeds I used to type at.
Last time I took a typing test (just for fun about 10 years ago) it was around 110 wpm.
Now that I had to slow down, it’s around 40 or 50.
For some reason, as a young kid I was motivated to teach myself touch typing. This was on a typewriter, long before computers became commonplace, at which point it became a really handy skill. I don’t know what my typing speed is but it’s pretty fast. Some might say (perhaps with some justification) that I type faster than I can think! 
I certainly make occasional typos but I can’t think of any that are common or systematic – my systematic mistakes tend to be at a higher level, more like mental lapses. Like omitting a necessary word altogether, or substituting an oddly inappropriate word because I’m thinking several words ahead and the brain slips a cog. One odd thing that happens quite frequently in my rapid-fire typing is writing “the” when I mean “that”. No idea what the mechanism is that causes that. Sometimes I have a chance to go back and fix it, sometimes not (curse you, five-minute timeout!).
For some reason that I can’t really fathom, I have a tendency to get ‘c’ and ‘s’ confused in uncommon words. It doesn’t happen a ton, but it happens way more then with any other letter substitution not caused by the keys being right next to each other. I don’t know if the fact that they sometimes make the same sound has anything to do with it.
I also have a tendency to double the letter, or much more frequently number, before the one I’m supposed to double. So instead of typing 833 I’ll do 883.
I transpose letters all the time. I’ve taken tests and I type with about 92% accuracy, which is not good for a writer.
Fortunately I am super fast (easily 100wpm) so it doesn’t slow me down much. Thinking about it, it’s probably the speed at which I type that makes it so easy to transpose letters. I do not look at the keyboard when I type unless I type a number or symbol wrong and need to make sure I get it right the second time.
I wish to improve my accuracy, but not sure how. A lot of typing programs are very basic.
Words ending …es are my nemesis - no idea why but the space bar seems to always get there before the ‘s’ … but it does make things interesting. I’ve lost count of the number of times I’ve typed ‘doe snot’ instead of ‘does not’ …
Have you tried hiring a nun with a ruler?
Constantly typing ; instead of '. So for instance I write it;s instead of it’s more often than the right way round.
Almost certainly, teh for the is my most common error.
My most bizarre error is to add extraneous m’s to the end of certain words that end in -me. So supreme comes out supremem and volume comes out volumem. I have no idea why I do that. I never make the same mistake when writing longhand.
I run an AutoHotkey script on my laptop that automatically corrects those sorts of errors, and the relatively few words I have trouble remembering how to spell, like threshold (to replace threshhold), practitioner (to replace practicioner), and pavilion (to replace pavillion).
Anything with an “in” in the final syllable turns into a terminating “-ing”. “Line” becomes “ling”, “intestine” is “intesting”, etc.
teh
Also have you noticed how “not” and “now” are essentially opposites of each other? It’s not a finger-slip, it’s some unconscious mistyping, but it’s still a common one.
Same as a couple of others in this thread. I often hit the space bar a letter too early. Less often, I forget to hit it at the end of a word. I usually catch that immediately so the second word is never completed.
I do exactly teh same. 
My solution is to use AutoHotKey to fix it. I’ve been using it happily for years.
The advantage is that it will do the autocorrect everywhere you type, whatever program you may be using. It monitors the keyboard input and modifies it instantly and invisibly.
All you need is one line in the AutoHotkey script file:
::teh::the
Set AutoHotKey to start up automatically with Windows (it uses only 2MB of memory, I just checked, and has no impact on speed), and you’ll never have to think about it again.
It will work for any similar autocorrects and abbreviations you want. You can also define hotkeys to input several lines of standard text, and do many other things. Highly recommended.
All of the above.
Plus overshooting the “delete” key and ejecting the CD drive.
teh for the
nad or adn for and
Doing the wrong keystroke for switching between languages and then having to go back and fix it again. This is more of a problem now because my home external keyboard does not function the same way as my office external keyboard.
And I keep typing Singth instead of Singh. I have no idea why I want to put a t in the name.
Learned keyboarding in high school as it was a prerequisite for Basic. I can touchtype in English, but not in German, mainly because I normally use an English keyboard layout and I don’t need to type much in German.
Of course, as with many coworkers, there is the odd kezboard error ever so often.
Certain words always get spelled wrong - I suspect the problem is worse than I realize because autocorrect is saving me. But I know I always type “commericial” for “commercial” and a few others.
This used to be awful. My left pinky is fairly twisted so when I type “a” it is leaning well over the key to the left of the “a”. Nowadays on most keyboards this is the caps lock key, so I will turn on all caps without realizing it.
BUT about 30 years ago I used a Sun UNIX workstation, whose keyboard put the ctrl key there. What I kept doing then was hitting ctrl-a, which in Microsoft Word would “select all”. The next letter I would type would replace my entire document with that letter. The letter after that would flush my entire document from the one-level-deep undo buffer. So, whenever I did this, I would lose all my work since the most recent save. I could try to remember to save every 10 seconds or so, but still.
Been years and at least one computer since I last used AutoKotKey to do general Windows-ish automation / app integration. But yeah, it was a good app back in the XP days and I’m pleased to know they’re still in biz. I never thought to use it as a real-time all-apps spelling corrector. I wonder if that capability existed way back then?
And yes, just before “XP” above I typed teh and had to go back and fix it.
My larger complaint with typos is that there’s no way I know of to edit the spellcheck dictionary Chrome uses. Yes, I can add my own words and maintain / edit that personal=local dictionary via Chrome’s settings. But I cannot remove a word from Chrome’s default dictionary. Which is a problem when they have a mistake or when I mistype one of my common words as one of their known good words, but it’s still the wrong word.