School time!
A few years back "Parrothead" started a thread about words and phrases that are commonly misused here on the forum... It was actually helpful for anyone interested in bettering their writing, especially ESL folks. Being a highschool English teacher, PH was well qualified for the task. I, on the other hand am sadly unqualified. Even so there are many simple mistakes that I see over and over again that stick out like a wrong note in a good song.
* Hanger vs. Hangar. (PH's pet peeve) The first is for hanging things on, the second is for storing aircraft.
* Apart vs. A part. Complete opposites. Many claim to love being "apart" of something without realizing it means they are separated from it while "a part" means they are with the in-crowd.
* a while vs. awhile. The first is a noun meaning a a span of time. The second is an adverb which qualifies an action.
* there, their, they're. They're all there in their places.
* To, Too, Two. The two of you can walk to the store unless it's too far.
Hopefully some folks who are more qualified than myself will contribute...