Have you been using the wrong word? Pin it so you can check it later.
Affect
verb
1. have an effect on; make a difference to.
Effect
noun
1. a change that is a result or consequence of an action or other cause.
What are some other words you’ve seen commonly misused?
-Eliabeth Hawthorne
Ermilia 
The above must not blind us to the proper use of ‘affect’ as a noun and ‘effect’ as a verb. Both have as specific meanings as the reversed usages in the illustration.
By the way, which of the following would you consider to be a misuse, or are they merely an example of divergence of idiom?
UK: “I couldn’t care less.”
USA: “I could care less.”
The UK version is the correct one. You are dismissing it saying that you care more about everything else than what is being discussed.
“I could not care less than I care about what we are discussing”
I would rather care about the weather than this
The US version is is saying that it is slightly important and that you could less about that than other stuff.
“I could care less than I care about what we are discussing”
I would rather care about this than the weather
Yes and no. Colloquial usage in America equates the second phrase to the same meaning as the ‘British’ one.
Oh wow
I think the main ones that are commonly misused are;
There, their, they’re and your, you’re, yore
I see those misused on Facebook all the time!
I don’t. But that could be because I deactivated my Facebook lol
I would deactivate mine, but I use it for work.
Funny thing is, I don’t miss it.
I have a pair of ‘uncommon’ ones:
Possess
1. have as belonging to one; own
2.of a demon or spirit, esp. an evil one) have complete power over (someone) and be manifested through their speech or actions.
and
Posses (plural of posse)
1.a body of men, typically armed, summoned by a sheriff to enforce the law.
That’s a good one. We caught a typo in one of the Blind Sight volumes that was similar. Assess and asses. Woops!
I don’t think I’ve done such mistakes yet but I caught some typos when my friends sent me messages. Like “weak, week”, “tired, tried”, “message, massage” etc. 🙂
By the way, the typo in your book is just hilarious. Assess and asses! 😉