Merriam Websters Top 10 Commonly Confused Words

My most frequently confused word did not make the list.  I don't know be happy or sad about this.

For me, it's peek and peak.

Even with the see and peek pneumonic (both have a double-e and both relate to vision), I still have to pause and consider the distinction whenever I use either word. 

I can also never remember how to spell calendar.  

So I understand when a writer confuses words.

But the one word pair that makes the list that should never be confused is its and it's, because...