Links Referred- http://www.thepunctuationguide.com/apostrophe.html
http://www.grammarbook.com/punctuation/apostro.asp
Apostrophe has three uses- contractions, plurals, and possessives.
With singular - noun's
Plural- nouns's
Incorrect: Since the 1980’s, the Thomas’s, both of whom have multiple PhD’s, sell old book’s and magazine’s at the fair on Saturday’s and Sunday’s.
Correct: Since the 1980s, the Thomases, both of whom have multiple PhDs, sell old books and magazines at the fair on Saturdays and Sundays.
The rare exception to the rule is when certain abbreviations, letters, or words are used as nouns, as in the following examples. Unless the apostrophe is needed to avoid misreading or confusion, omit it.
He received four A’s and two B’s.
We hired three M.D.’s and two D.O.’s.
Be sure to cross your t’s and dot your i’s.
Do we have more yes’s than no’s?
For this last example, the trend is to instead write yeses and noes.
The general rule for forming possessives
The general rule is that the possessive of a singular noun is formed by adding an apostrophe and s, whether the singular noun ends in s or not.
the lawyer’s fee
the child’s toy
Xerox’s sales manager
Tom Jones’s first album
Jesus’s disciples
Aeschylus’s finest drama
anyone’s guess
a week's vacation
The possessive of a plural noun is formed by adding only an apostrophe when the noun ends in s, and by adding both an apostrophe and s when it ends in a letter other than s.
excessive lawyers’ fees
children’s toys
the twins’ parents
the student teachers’ supervisor
the Smiths’ vacation house
the boys’ baseball team
the alumni’s fundraising
someone with twelve years’ experience
Exceptions to the general rule
Use only an apostrophe for places or names that are singular but have a final word in plural form and ending with an s.
Beverly Hills’ current mayor
the United States’ lingering debt problem
Cisco Systems’ CEO
Nouns that end in an s sound take only an apostrophe when they are followed by sake.
for goodness’ sake
for conscience’ sake
A proper noun that is already in possessive form is left as is.
T.G.I. Friday’s menu was recently changed.
Joint possession with single apostrophe
Individual with single apostrophe
Stanley and Scarlett’s house. (they share the house)
Chris’s and John’s houses were designed by the same architect.
The apostrophe with other punctuation
The apostrophe should never be separated from the word to which it attaches by adjacent punctuation.
Correct: The house on the left is the Smiths’, but the house at the end of the street is the Whites’.
Incorrect: The house on the left is the Smiths,’ but the house at the end of the street is the Whites.’
a. Contractions- Let's, don't, couldn't, it's , she's
e.g. It's often said that every dog has its day.
Plurals
Apostrophe is seldom used to form a plural noun.
Last 2 digits preceded by an apostrophe -(the class of '85, pop music from the '80s)
- With Single Noun- woman's hat, boss's wife, chang's house
- Complicated- Lens, cactus, bus, Jones, Texas, Christmas. NO RULE BUT STAT CONSISTENT.
- Class's hour, Jones' golf clubs, canvas's size, Texas' weather.
