The Poor Apostrophe
It seems many people think the poor apostrophe is so underused in the English language that they take it upon themselves to use it all over the place, even when it’s completely incorrect. One of my biggest peeves is when the spelling of the possessive form of “it” is spelled with an apostrophe. True, an apostrophe is normally used to indicate possession. However, the possessive form of “it” is “its” with no mark. “It’s” is only correct when indicating the contraction of “it is” or “it has.”
Another very common and very incorrect use is in making a word plural. Most plural forms are made by appending an “s” or “es” to the end of the word. No extra marks are necessary. Even acronyms should simply have an “s” added (e.g., “VCRs”).
I came across a great cartoon drawing that summarizes the rules perfectly. Check it out.