Apostrophe was not a Greek philosopher

As threatened, a much needed and highly subjective little primer on the use of apostrophes.  Pay attention class.

For several months the horrid pub on our corner displayed the following sign, see if you can spot the problem:

Toilet's are for customer's use only!

The correct answer is, of course, that the sign is redundant.  No one who wasn't suicidally insane would ever think of entering one of their tiled gas chambers.

Eventually one of their patrons must have sobered up enough to point out to the management that "Toilet's" is a possessive, implying that something belongs to the toilet.  However, in their quasi inebriated state they undoubtedly neglected to mention that in the case of nouns which are made plural by adding an "s" at the end, the "s" after the apostrophe is not used.  Thus if the sign writer wished to convey that something belonged to the toilets, the correct usage would be "toilets' ".

Several conversations along these lines must have occurred because the sign went through a rapid series of revisions:

Toilets are for customers use only!

Toilet are for customer use only!

Toilet's are for customers use only!

At last, after all exhausting all other options, they settled on the sign that graces the front door of the pub today:

Toilets are for customer's use only!

Hallelujah.

To be slightly more clear: singular nouns that don't end in "s" (or an "s" sound), are made possessive by adding an apostrophe "s".  Plural nouns that do end in an "s" get an apostrophe after the "s".

• the cat's meow
• the dog's dinner
• two flags' stripes
• thirteen ships' rum pots

These rules also apply when we are talking about time, and since time=money we can safely assume that the rules apply to it as well.

•  A dollar's worth of crack
•  One afternoon's fun
  
• Twenty years' jail time
• Many nights' regret

For singular nouns and proper names which end in an "s" you are on your own.  Cross'  is just as good as cross's and Lewis' works as well as Lewis's.  If it sounds good, that's the one you use.

Just to fry your noodles: if a plural noun is not one formed by adding an "s" (like women,  sheep or rice) then you need to add an apostrophe "s" to indicate possession: women's, sheep's, rice's.  The same is true for nouns which change their spelling as plurals (and end with an "s" or "z" sound): mice and dice become mice's and dice's although to be fair those do sound a bit strange.

There are about three-quarters of a million words in the English language but there are only seven possessive pronouns that don't get an apostrophe tacked onto the end.  They are, in an order which makes a nice shape:

• yours
• hers
  
• his
  
• its
• ours
• theirs
• whose
  

Every single other possessive pronoun gets an apostrophe: everyone's, somebody's, one's, etc.  People who have received government grants tell us that even the most blind-drunk football fan can easily memorize a series of seven digits or short words, if you are that fan, make these your words.

Lest I forget, for the love of God, "it's" is a contraction of "it is" or "it has" NOT the possessive of "it."  If "it" owns something you write it like this: "...its very own little black dress..."

Style guides for the use of apostrophes are like thermometers and religious sects, no two agree.  Even when they do you can come up with some truly bizarre, if perfectly grammatically correct sentences:

• My lovers' friend's sex toys (the sex toys belonging to a lover of several of my friends)

I'm going to skip over all that nonsense like it were somebody else's problem and finish off with dates and sins of omission.

Dates

• The nineteen sixties: The 1960s
• The twenties: The 20s or The '20s
  
• Thousands of years: 1000s of years

Omitted characters

• In contractions (remember the last lesson?): they're for they are, I'll for I will or I shall, ma'am for madam
  
• In abbreviations:  gov't for government
  

There are pages and pages of additional rules governing apostrophes but I've grown bored of the subject so I will leave it up to you to Google any specifics that I might have missed.  Be warned, the improper use of an apostrophe in an otherwise lucid article, e-mail or birthday card is a salient reminder to the reader of that you are lacking in education, moral fiber and don't know the proper order to apply clotted cream and jam to a scone. 

Next up: defective people