Whose holiday is this anyway?
Is this Presidents Day, President’s Day or Presidents’ Day?
The federal holiday that occurs on the third Monday of February is actually called Washington’s Birthday but some states have combined his birthday with Lincoln’s.
If the holiday is to celebrate the birthdays of multiple presidents it should be plural possesive: Presidents’ Day.
A single object belonging to two people
If two people own one thing, put the possessive apostrophe after the second name.
Chet Huntley and David Brinkley’s evening news program ended in 1970.
[this was a co-anchored news program]
If two people own different items, put the apostrophe after both names.
Dave Letterman’s and Jay Leno’s TV shows feature comedy and guests.
[these are separate shows on separate networks]
Combining two independent clauses.
”Independent clause” is really just another name for a simple sentence.
When you join two independent clauses, do one of the following:
separate them with a semicolon:
I didn’t want the bananas to spoil; I ate them all that evening.
separate them with a coordinating conjunction (and, but, for, nor, or, so, yet):
I didn’t want the bananas to spoil, so I ate them all that evening.
make them separate sentences:
I didn’t want the bananas to spoil. I ate them all that evening.
Do not separate two independent clauses with a comma.
How do I punctuate the end of these sentences?
The punctuation at the end of a quotation goes inside the quotation marks:
“. . . and dedicated to the proposition that all men are created equal.”
When several words of a quote are missing, use ellipses without ending punctuation:
“. . . and dedicated to the proposition that all men . . .”
When the last word of a quote is missing, use ellipses and the ending punctuation:
“. . . and dedicated to the proposition that all men are created . . . .”
When a sentence ends with an abbreviation, do not add an extra period:
The movie starts at 7 p.m.
When a question ends with an abbreviation, add the question mark:
Does the sun rise today before 6 a.m.?
When a sentence ends with an acronym, add the ending punctuation:
He had been an employee of NASA.
When an entire sentence is enclosed in parentheses, place the punctuation inside:
(He had hoped it would be kept a secret.)
When the end of a sentence is enclosed in parentheses, place the punctuation outside:
He had written a diary (which he had hoped would be kept private).
A questionable topic
Who, what, why, when, where and how do not always require a question mark.
Where is he going?
I wonder where he is going.
This is the country where he was born.
I go where he goes.
Apostrophes
One final pet peeve concerning apostrophes incorrectly used with plurals.
Almost all plurals that are not possessives do not use apostrophes.
Use PCs, not PC’s.
Use TVs, not TV’s.
Use tacos, not taco’s.
Use hundreds, not hundred’s.
Use pizzas, not pizza’s.
Use “Way to go, Vikings!” not “Way to go, Viking’s!”
Exceptions are the plurals of letters and numbers.
There are two s’s in that word.
She dots all her i’s and crosses all her t’s.
My son can say his 1’s, 2’s, and 3’s in five different languages.
Three posts are more than enough to spend on these misused apostrophes and might even cause you to join this group:

Lets discard the apostrophe. Its pointless.
Apostrophes
Apostrophes (‘) are used for three reasons: possession (boy’s bike), contraction (don’t) or omission (Rock ‘n’ Roll). Today I’ll cover contractions and omissions.
For both contractions and omissions, the apostrophe replaces the missing letter.
Contraction examples would be:
you’re for you are, where it replaces the a in are
it’s for it is where the apostrophe replaces the i in is
Omission examples would be:
gone fishin’ where the apostrophe replaces the g
pot o’ gold where the apostrophe replaces the f
rock ’n’ roll where the apostrophe replaces the a and d in and
In a date when part of the year is left out, the apostrophe needs to indicate the missing year. In the 80s would mean the temperature; In the ‘80s would mean the decade.
Apostrophes
Apostrophes (’) are used for three reasons: possession (boy’s bike), contraction (don’t) or omission (Rock ’n’ Roll). Today I’ll cover possession.
If the owner is singular, add the apostrophe before the s. The boy’s book.
If the owner is plural, add the apostrophe after the s. The girls’ sleepover.
If the owner is plural without an s, add ’s. The women’s room.
It the owner is it, do not add an apostrophe. The court said its decision was fair.
Do not add an apostrophe on plural words that are not possessive. The dogs barked.
Quotation marks
There are two basic rules:
Commas and periods always go inside the quotation marks.
Question marks and exclamation points go in or out, depending on whether they are part of the material being quoted.
There is much more to this topic and for that I refer you to
English Grammar for Dummies. I need to review that chapter myself before I do any serious quoting.
One space between sentences.
On a typewriter you might have been taught to place two spaces after a sentence. That does not apply to typing on a computer. Since computers use proportional fonts, where the space taken by each character varies, two spaces can leave a disturbing gap. This also applies to all other punctuation marks.