From the “it’s my blog and I’ll do what I want” school: oh YES I CAN lecture on grammar!
The apostrophe (‘) is a punctuation mark used for two things and pretty much nothing else. Its uses are:
1. Contractions: when you use two words together and use the apostrophe to show where letters are removed.
Examples: won’t (will not), don’t (do not), aren’t (are not), it’s (it is), she’s (she is), we’re (we are), you’re (you are), I’ll (I will).
2. Possessives: used to show ownership, belonging, relationship, but NOT with pronouns.
Correct: It’s no fun to trim the cat’s claws, but it does make some hilarious video.
(The “it’s” is short for “it is,” therefore a contraction, which needs an apostrophe. The claws belong to the cat, therefore “cat’s” is possessive, hence the apostrophe. “Claws,” however, is a plural noun, and NOT used in the possessive case, therefore no apostrophe is used.)
Those two constructions are the only times that apostrophes are used in the English language. THEY ARE NOT USED IN PLURAL NOUNS. There are few exceptions to this rule, they are ambiguous at best, and they are not frequently necessary.
The plural of a proper noun (name) is not an exception. The plural of a word ending in a vowel sound is not an exception. If the noun ends in an “s” to show that there is more than one, there is no apostrophe. I will resort to using Harry Potter for examples.
Incorrect: Harry Potter likes to stay with the Weasley’s during the summer holiday’s.
(The Weasley’s what? Which Weasley are we talking about, anyway? The holiday’s what?)
The sentence should read: Harry Potter likes to stay with the Weasleys during the summer holidays.
Correct: Harry Potter likes to stay with his best friend Ron Weasley’s family during the summer holidays.
(Ron is singular, the family pertains to him, therefore we use the possessive apostrophe.)
Another bad example: The in-law’s are coming over to look after the kid’s.
(Which in-law’s what are coming over? The kid’s what needs to be looked after?)
Correct: The in-laws are coming over to look after the kids.
(It’s the same sentence but with two fewer keystrokes. Using apostrophes correctly means less time spent typing!)
Does that make sense? Contractions, possessive nouns: use apostrophes.
Plural nouns: apostrophes are not only unnecessary but, in fact, wrong. Save your keystrokes.