Adding an extra full-stop or the wrong letter

Yes, you’re only human, and humans make typos. But one little error might be all it takes to lower your grade on that exam, or to ruin your resume. As tempting as it may be to rely on spell check to catch all of your goofs, the tool has its limits, and it can’t play the role of a careful pair of proofreading eyes.
Humans make errors, sure – but in these nine cases, they can also fix them way more effectively than a computer can.
The wrong word

Spell check does just that: catches words that are spelled wrong. But if you write the wrong word altogether, spell check won’t save you if that word is spelled correctly. If you type ‘their’ instead of ‘there,’ ‘you’re’ instead of ‘your,’ or, like this poor woman, ‘manure’ instead of ‘mature,’ it’s up to you to correct the error.
The wrong name

If you frequently have to compose the same email or message to several different people, it can be tempting to copy and paste the entire message. But never do that without reading over the message first. If it says ‘Dear Steve’ but you’re writing to Julie…well, that’s just plain embarrassing – not to mention, if Julie is a potential employer, it could cost you the job offer.