PUNCTUATION MARKS

Punctuation is the system of signs or symbols given to a reader to show how a sentence is constructed and how it should be read.

Punctuation is used to create sense, clarity and stress in sentences. You use punctuation marks to structure and organise your writing.

We use a variety of punctuation marks, such as full stop/period, comma, question mark, brackets, etc. in our writing to separate sentences, phrases, etc., and to clarify their meaning. We need to familiarize ourselves with some basic rules in order to use these punctuation marks correctly.

SENTENCE ENDINGS

Three of the fourteen punctuation marks are appropriate for use as sentence endings. They are the period, question mark, and exclamation point.

THE PERIOD OR FULL STOP (.) is placed at the end of declarative sentences, statements thought to be complete and after many abbreviations. A full stop is placed at the end of each sentence to indicate the end of the sentence, which can be a statement, request or command. A full stop is not used at the end of a phrase or subordinate clause. Doing so does not create complete sentences.

For example:

•  As a sentence ender: I am going home.

•  After an abbreviation: Her septbirthday came and went.

Usage of Full Stop or Period (.)

a. The period is used after most abbreviations:

Example: Mr., Mrs., Ms., Dr., Rev. Wed., Oct.

b. Most short versions of some specific expressions end in a period.

Example: A.M./a.m., P.M./p.m., p.a.

c. Only one full stop is used if a sentence ends with an abbreviation.

Example: Her biggest ambition is to successfully complete her M.A.

d. The period is used to show the shortened form of a word.

Example: Opp., mo. (Written abbreviations of ‘opposite’, ‘month’)

e. A full stop is always placed inside quotation marks, whether or not it is part of the quotation.

Example: John said, “That stray dog is not mine.”
NOT: John said, “That stray dog is not mine”.

The question mark (?) is used

  • to indicate a direct question when placed at the end of a sentence.

E.g.: When did Jane leave for the market ?

  • A question mark is used after a question that ends with an abbreviation.

E.g.: You said you saw the film show at about 7 p.m.?

THE EXCLAMATION MARK (!) is used when a person wants to express a sudden outcry or add emphasis. An exclamation mark is used after interjections or commands. (An interjection is a word or phrase used to express a strong feeling.) It expresses an emotion such as surprise, anger, fear, pain or pleasure.

  1. Within dialogue: “Holy moses!” screamed Joke.
  2. To emphasize a point: My sister-in-law’s rants make me furious !
  3. To express an emotion: What a complete waste of resources! / Sit over there and be quiet for an hour!

THE COMMA (,)

The comma, semicolon and colon are often misused because they all can indicate a pause in a series.

The comma is used to show a separation of ideas or elements within the structure of a sentence. Additionally, it is used in letter writing after the salutation and closing.

  • Separating elements within sentences: Suzi wanted the black , green, red, pink, white and blue shoes.

Note that in a list, the final two items are linked by the word ‘and’ rather than by a comma.

  • Letter Salutations: Dear Uncle Jola , Dear Miss Busola,
  • Separation of two complete sentences: We went to the theatre, and we went to the beach.

The comma is useful in a sentence when the writer wishes to:

pause before proceeding

add a phrase that does not contain any new subject

separate items on a list

use more than one adjective (a describing word, like beautiful)

For example, in the following sentence the phrase or clause between the commas gives us more information behind the actions of the boy, the subject of the sentence:

The boy, who knew that his mother was about to arrive, ran quickly towards the opening door.

THE COLON (:)

A colon (:) has two main uses:

The first is after a word introducing a quotation, an explanation, an example, or a series. It is also often used after the salutation of a business letter.

The second is within time expressions. Within time, it is used to separate out the hour and minute: 11:00am.

A colon is used before a list and usually after ‘as follows.’

E.g.: This basket contains the following fruits: mango, pawpaw, watermelon, apple and pineapple.

It is used to separate the hour from the minutes when telling time

E.g.: 12:13am

It can be used within a heading, or descriptive title.

Example:

Comedy or Reality: A man slapped his wife over lunch.

SEMI-COLON (;)

The semi-colon is perhaps the most difficult sign of punctuation to use accurately.  If in doubt, avoid using it and convert the added material into a new sentence.

As a general rule, the semi-colon is used in the following ways:

A semicolon is used to join two sentences, independent clauses or a series of items which are closely connected in meaning.

Examples:

We leave for Ibadan at noon; the weather looks promising.

He gives up smoking; obviously, he fears contracting one of the smoking-related diseases

The semi-colon can also be used to assemble detailed lists.

E.xamples:

The conference was attended by delegates from Ikeja, Lagos; Agbowo, Ibadan; Wuse, Abuja; Daura, Katsina; and Sabongari, Kano.

The semicolon (;) is used to connect independent clauses. It shows a closer relationship between the clauses than a period would show. For example: John was hurt ; he knew she only said it to upset him.

THE APOSTROPHE (‘)

An apostrophe (‘) sometimes called inverted comma is used to indicate the omission of a letter or letters from a word, the possessive case, or the plurals of lowercase letters.

  • The apostrophe indicates possession or ownership.

For example:

The boy’s car is red, (girl is in the singular).

This shows the reader that the car belongs to the boy.

The boys’ cars are green, (boys in this instance are plural, i.e. more than one boy, more than one car).

This indicates that the cars belong to the boys.

  • to form contractions by showing the numbers or letters that have been left out.

E.g.: ’89 =1989
E.g.: I am = I’m / we are = we’re / he will, you’re

  • to form the possessive of a noun.

Add ‘s to a single noun or name: uncle’s pipe; Tony’s girlfriend; dog’s tail; Bobola’s car.
Add ‘s to singular noun that end in –s: actress’s role; princess’s lover; rhinoceros’s skin.
Add ‘s to plural nouns that end in –s: boys’ bicycles; friends’ houses; books’ covers
Add ‘s to other plural nouns: children’s toys; women’s clothes; men’s boots.
Add ‘s to a person’s office or shop: I’ll buy the pork at the butcher’s. / I’ll be visiting Tom’s.
Add ‘s only after the second name: Jack and Jill’s pail; Bonnie and Clyde’s loot.

  • to form the plural of abbreviations: many Dr.’s; many M.D.’s; many Ph.D.’s.

QUOTATION OR SPEECH MARKS (“….”)

Quotation or speech marks are used to:

To mark out speech

When quoting someone else’s speech

For example:

My grandma said, “Share your chocolates with your friends.”

“George, don’t do that!”

“Will you get your books out please?” said Mrs Jones, the teacher, “and quieten down!”

HYPHEN (-)

The hyphen is used to link words together.

For example:

  • twentieth-century people
  • second-class upper
  • non-verbal

Generally, hyphens are used to join two words or parts of words together while avoiding confusion or ambiguity.

EXAMPLES

show-down

up-to-date

There are some cases where hyphens preserve written clarity such as where there are letter collisions, where a prefix is added, or in family relations. Many words that have been hyphenated in the past have since dropped the hyphen and become a single word (email, nowadays).

EXAMPLES

  • co-operate
  • oval-like
  • anti-bomb
  • post-colonial
  • great-grandmother
  • mother-in-law

HYPHENS IN NUMBERS

Hyphen is used with compound numbers from twenty-one to ninety-nine.

EXAMPLES

  • Twenty-two
  • seventy-five
  • thirty-three
  • sixty-nine

In written fractions, a hyphen is placed between the numerator and denominator except if there is already a hyphen in either the numerator or the denominator.

EXAMPLES

two-thirds

one-eight

three-tenths

six-hundredths

A Hyphen is used when a number forms part of an adjectival compound

EXAMPLES

Bobola has a 55-hour working week.

Busola won the 12000-metre marathon race.

Wole Soyinka was a great nineteenth-century novelist.

DASHES

Dashes can be used to add parenthetical statements or comments in much the same way as you would use brackets. In formal writing you should use the bracket rather than the dash as a dash is considered less formal. Dashes can be used to create emphasis in a sentence.

EXAMPLES

You may think she is a liar – she isn’t.

Osas might come to the party – you never know.

BRACKETS (   )

Brackets always come in pairs (  ) and are used to make an aside, or a point which is not part of the main flow of a sentence.  If you remove the words between the brackets, the sentence should still make sense.

For example:

“The strategy (or strategies) chosen to meet the objectives may need to change as the intervention continues.”

SQUARE BRACKETS

[…]

A different set of square brackets [   ] can be used:

to abbreviate lengthy quotations

to correct the tense of a quotation to suit the tense of your own sentence

to add your own words to sections of an abbreviated quotation.

To abbreviate lengthy quotations in an essay or report

Example:

“We can define class as a large-scale grouping of people who share common economic resources that strongly influence the types of lifestyle they are able to lead.  Ownership of wealth, together with occupation, are the chief basis of class differences.  The major classes that exist in Western societies are an upper class […]; a middle class […] and a working class […].”

SLASH (/)

Many people use the slash instead of or, and etc., but this is not always helpful to the reader.  There is, however, a modern convention in gender-neutral writing to use ‘s/he’.

Slashes are important symbols in web-addresses (URLs). The full URL for this page is https://www.passnownow.com/classwork-support/

ELLIPSIS (…)

An ellipsis (three dots) indicates that part of the text has been intentionally been left out.

Example: List of odd numbers between 1 and 99 – 1,3,5,… 99.

Punctuation Rules

Since proper punctuation is an essential part of successful communication, remembering basic punctuation rules will make it easier for you to write clearly and effectively.

  • Periods
  • Commas
  • Semicolons
  • Colons
  • Quotation Marks
  • Parentheses and Brackets
  • Apostrophes

Periods

Rule 1. Use a period at the end of a complete sentence that is a statement.

Example: I know him well.

Rule 2. If the last item in the sentence is an abbreviation that ends in a period, do not follow it with another period.

Incorrect: This is Alice Smith, M.D..

Correct: This is Alice Smith, M.D.

Correct: Please shop, cook, etc. We will do the laundry.

Rule 3. Question marks and exclamation points replace and eliminate periods at the end of a sentence.

Commas

Commas and periods are the most frequently used punctuation marks. Commas customarily indicate a brief pause; they’re not as final as periods.

Rule 1. We use commas to separate words and word groups in a simple series of three or more items.

Example: My estate goes to my husband, son, daughter-in-law, and nephew.

Note: When the last comma in a series comes before and or or (after daughter-in-law in the above example), it is known as the Oxford comma. Most newspapers and magazines drop the Oxford comma in a simple series, apparently feeling it’s unnecessary. However, omission of the Oxford comma can sometimes lead to misunderstandings.

Example: We had coffee, cheese and crackers and grapes.

Adding a comma after crackers makes it clear that cheese and crackers represents one dish. In cases like this, clarity demands the Oxford comma.

We had coffee, cheese and crackers, and grapes.

Fiction and nonfiction books generally prefer the Oxford comma. Writers must decide Oxford or no Oxford and not switch back and forth, except when omitting the Oxford comma could cause confusion as in the cheese and crackers example.

Semicolons

It’s no accident that a semicolon is a period atop a comma. Like commas, semicolons indicate an audible pause—slightly longer than a comma’s, but short of a period’s full stop.

Semicolons have other functions, too. But first, a caveat: avoid the common mistake of using a semicolon to replace a colon (see the “Colons” section).

Incorrect: I have one goal; to find her.

Correct: I have one goal: to find her.

Rule 1. A semicolon can replace a period if the writer wishes to narrow the gap between two closely linked sentences.

Examples:
Call me tomorrow; you can give me an answer then.
We have paid our dues; we expect all the privileges listed in the contract.

Rule 2. Use a semicolon before such words and terms as namely, however, therefore, that is, i.e., for example, e.g., for instance, etc., when they introduce a complete sentence. It is also preferable to use a comma after these words and terms.

Example: Bring any two items; however, sleeping bags and tents are in short supply.

Rule 3. Use a semicolon to separate units of a series when one or more of the units contain commas.

Incorrect: The conference has people who have come from Moscow, Idaho, Springfield, California, Alamo, Tennessee, and other places as well.

Note that with only commas, that sentence is hopeless.

Correct: The conference has people who have come from Moscow, Idaho; Springfield, California; Alamo, Tennessee; and other places as well.

Rule 4. A semicolon may be used between independent clauses joined by a connector, such as and, but, or, nor, etc., when one or more commas appear in the first clause.

Example: When I finish here, and I will soon, I’ll be glad to help you; and that is a promise I will keep.

 Colons

A colon means “that is to say” or “here’s what I mean.” Colons and semicolons should never be used interchangeably.

Rule 1. Use a colon to introduce a series of items. Do not capitalize the first item after the colon (unless it’s a proper noun).

Examples:
You may be required to bring many things: sleeping bags, pans, utensils, and warm clothing.
I want the following items: butter, sugar, and flour.
I need an assistant who can do the following: input data, write reports, and complete tax forms.

Rule 2. Avoid using a colon before a list when it directly follows a verb or preposition.

Incorrect: I want: butter, sugar, and flour.

Correct:
I want the following: butter, sugar, and flour.
OR
I want butter, sugar, and flour.

Incorrect: I’ve seen the greats, including: Barrymore, Guinness, and Streep.

Correct: I’ve seen the greats, including Barrymore, Guinness, and Streep.

Rule 3. When listing items one by one, one per line, following a colon, capitalization and ending punctuation are optional when using single words or phrases preceded by letters, numbers, or bullet points. If each point is a complete sentence, capitalize the first word and end the sentence with appropriate ending punctuation. Otherwise, there are no hard and fast rules, except be consistent.

Examples:

I want an assistant who can do the following:

  1. input data
  2. write reports
  3. complete tax forms

The following are requested:

  • Wool sweaters for possible cold weather.
  • Wet suits for snorkeling.
  • Introductions to the local dignitaries.

These are the pool rules:

  1. Do not run.
  2. If you see unsafe behavior, report it to the lifeguard.
  3. Did you remember your towel?
  4. Have fun!

Rule 4. A colon instead of a semicolon may be used between independent clauses when the second sentence explains, illustrates, paraphrases, or expands on the first sentence.

Example: He got what he worked for: he really earned that promotion.

If a complete sentence follows a colon, as in the previous example, it is up to the writer to decide whether to capitalize the first word. Capitalizing a sentence after a colon is generally a judgment call; if what follows a colon is closely related to what precedes it, there is no need for a capital.

Note: A capital letter generally does not introduce a simple phrase following a colon.

Example: He got what he worked for: a promotion.

Rule 5. A colon may be used to introduce a long quotation. Some style manuals say to indent one-half inch on both the left and right margins; others say to indent only on the left margin. Quotation marks are not used.

Example: The author of Touched, Jane Straus, wrote in the first chapter:
Georgia went back to her bed and stared at the intricate patterns of burned moth wings in the translucent glass of the overhead light. Her father was in “hyper mode” again where nothing could calm him down.

Rule 6. Use a colon rather than a comma to follow the salutation in a business letter, even when addressing someone by his or her first name. (Never use a semicolon after a salutation.) A comma is used after the salutation in more informal correspondence.

Formal: Dear Ms. Rodriguez:

Informal: Dear Dave,

 Quotation Marks

The rules set forth in this section are customary in the United States. Great Britain and other countries in the Commonwealth of Nations are governed by quite different conventions. Nowhere is this more apparent than in Rule 3a in this section, a rule that has the advantage of being far simpler than Britain’s and the disadvantage of being far less logical.

Rule 1. Use double quotation marks to set off a direct (word-for-word) quotation.

Correct: “When will you be here?” he asked.

Incorrect: He asked “when I would be there.”

Rule 2. Either quotation marks or italics are customary for titles: magazines, books, plays, films, songs, poems, article titles, chapter titles, etc.

Rule 3a. Periods and commas always go inside quotation marks.

Examples:
The sign said, “Walk.” Then it said, “Don’t Walk,” then, “Walk,” all within thirty seconds.
He yelled, “Hurry up.”

Rule 3b. Use single quotation marks for quotations within quotations.

Example: He said, “Dan cried, ‘Do not treat me that way.’ “

Note that the period goes inside both the single and double quotation marks.

Rule 4. As a courtesy, make sure there is visible space at the start or end of a quotation between adjacent single and double quotation marks. (Your word processing program may do this automatically.)

Not ample space: He said, “Dan cried, ‘Do not treat me that way.'”

Ample space: He said, “Dan cried, ‘Do not treat me that way.’ “

Rule 5a. Quotation marks are often used with technical terms, terms used in an unusual way, or other expressions that vary from standard usage.

Examples:
It’s an oil-extraction method known as “fracking.”
He did some “experimenting” in his college days.
I had a visit from my “friend” the tax man.

Rule 5b. Never use single quotation marks in sentences like the previous three.

Incorrect: I had a visit from my ‘friend’ the tax man.

The single quotation marks in the above sentence are intended to send a message to the reader that friend is being used in a special way: in this case, sarcastically. Avoid this invalid usage. Single quotation marks are valid only within a quotation, as per Rule 3b, above.

Rule 6. When quoted material runs more than one paragraph, start each new paragraph with opening quotation marks, but do not use closing quotation marks until the end of the passage.

Example: She wrote: “I don’t paint anymore. For a while I thought it was just a phase that I’d get over.
“Now, I don’t even try.”

 Parentheses and Brackets

Parentheses and brackets must never be used interchangeably.

Parentheses

Rule 1. Use parentheses to enclose information that clarifies or is used as an aside.

Example: He finally answered (after taking five minutes to think) that he did not understand the question.

If material in parentheses ends a sentence, the period goes after the parentheses.

Example: He gave me a nice bonus ($500).

Commas could have been used in the first example; a colon could have been used in the second example. The use of parentheses indicates that the writer considered the information less important—almost an afterthought.

Rule 2. Periods go inside parentheses only if an entire sentence is inside the parentheses.

Example: Please read the analysis. (You’ll be amazed.)

This is a rule with a lot of wiggle room. An entire sentence in parentheses is often acceptable without an enclosed period:

Example: Please read the analysis (you’ll be amazed).

Rule 3. Parentheses, despite appearances, are not part of the subject.

Example: Joe (and his trusty mutt) was always welcome.

If this seems awkward, try rewriting the sentence:

Example: Joe (accompanied by his trusty mutt) was always welcome.

Rule 4. Commas are more likely to follow parentheses than precede them.

Incorrect: When he got home, (it was already dark outside) he fixed dinner.

Correct: When he got home (it was already dark outside), he fixed dinner.

Brackets

Brackets are far less common than parentheses, and they are only used in special cases. Brackets (like single quotation marks) are used exclusively within quoted material.

Rule 1. Brackets are interruptions. When we see them, we know they’ve been added by someone else. They are used to explain or comment on the quotation.

Examples:
“Four score and seven [today we’d say eighty-seven] years ago…”
“Bill shook hands with [his son] Al.”

Rule 2. When quoting something that has a spelling or grammar mistake or presents material in a confusing way, insert the term sic in italics and enclose it in nonitalic (unless the surrounding text is italic) brackets.

Sic (“thus” in Latin) is shorthand for, “This is exactly what the original material says.”

Example: She wrote, “I would rather die then [sic] be seen wearing the same outfit as my sister.”

The [sic] indicates that then was mistakenly used instead of than.

Rule 3. In formal writing, brackets are often used to maintain the integrity of both a quotation and the sentences others use it in.

Example: “[T]he better angels of our nature” gave a powerful ending to Lincoln’s first inaugural address.

Lincoln’s memorable phrase came midsentence, so the word the was not originally capitalized.

Apostrophes

Rule 1a. Use the apostrophe to show possession. To show possession with a singular noun, add an apostrophe plus the letter s.

Examples:
a woman’s hat
the boss’s wife
Mrs. Chang’s house

Rule 1b. Many common nouns end in the letter s (lens, cactus, bus, etc.). So do a lot of proper nouns (Mr. Jones, Texas, Christmas). There are conflicting policies and theories about how to show possession when writing such nouns. There is no right answer; the best advice is to choose a formula and stay consistent.

Rule 1c. Some writers and editors add only an apostrophe to all nouns ending in s. And some add an apostrophe + s to every proper noun, be it Hastings’s or Jones’s.

One method, common in newspapers and magazines, is to add an apostrophe + s (‘s) to common nouns ending in s, but only a stand-alone apostrophe to proper nouns ending in s.

Examples:
the class’s hours
Mr. Jones’ golf clubs
the canvas’s size
Texas’ weather

Care must be taken to place the apostrophe outside the word in question. For instance, if talking about a pen belonging to Mr. Hastings, many people would wrongly write Mr. Hasting’s pen (his name is not Mr. Hasting).

Correct: Mr. Hastings’ pen

Another widely used technique is to write the word as we would speak it. For example, since most people saying, “Mr. Hastings’ pen” would not pronounce an added s, we would write Mr. Hastings’ pen with no added s. But most people would pronounce an added s in “Jones’s,” so we’d write it as we say it: Mr. Jones’s golf clubs. This method explains the punctuation of for goodness’ sake.

Rule 2a. Regular nouns are nouns that form their plurals by adding either the letter s or -es (guy, guys; letter, letters; actress, actresses; etc.). To show plural possession, simply put an apostrophe after the s.

Correct: guys’ night out (guy + s + apostrophe)

Incorrect: guy’s night out (implies only one guy)

Correct: two actresses’ roles (actress + es + apostrophe)

Incorrect: two actress’s roles

Rule 2b. Do not use an apostrophe + s to make a regular noun plural.

Incorrect: Apostrophe’s are confusing.

Correct: Apostrophes are confusing.

Incorrect: We’ve had many happy Christmas’s.

Correct: We’ve had many happy Christmases.

In special cases, such as when forming a plural of a word that is not normally a noun, some writers add an apostrophe for clarity.

Example: Here are some do’s and don’ts.

In that sentence, the verb do is used as a plural noun, and the apostrophe was added because the writer felt that dos was confusing. Not all writers agree; some see no problem with dos and don’ts.

Rule 2c. English also has many irregular nouns (child, nucleus, tooth, etc.). These nouns become plural by changing their spelling, sometimes becoming quite different words. You may find it helpful to write out the entire irregular plural noun before adding an apostrophe or an apostrophe + s.

Incorrect: two childrens’ hats

The plural is children, not childrens.

Correct: two children’s hats (children + apostrophe + s)

Incorrect: the teeths’ roots

Correct: the teeth’s roots

Rule 2d. Things can get really confusing with the possessive plurals of proper names ending in s, such as Hastings and Jones.

If you’re the guest of the Ford family—the Fords—you’re the Fords’ guest (Ford + s + apostrophe). But what if it’s the Hastings family?

Most would call them the “Hastings.” But that would refer to a family named “Hasting.” If someone’s name ends in s, we must add -es for the plural. The plural of Hastings is Hastingses. The members of the Jones family are the Joneses.

To show possession, add an apostrophe.

Incorrect: the Hastings’ dog

Correct: the Hastingses’ dog (Hastings + es + apostrophe)

Incorrect: the Jones’ car

Correct: the Joneses’ car

In serious writing, this rule must be followed no matter how strange or awkward the results.

Rule 2e. Never use an apostrophe to make a name plural.

Incorrect: The Wilson’s are here.

Correct: The Wilsons are here.

Incorrect: We visited the Sanchez’s.

Correct: We visited the Sanchezes.

Rule 3. With a singular compound noun (for example, mother-in-law), show possession with an apostrophe + s at the end of the word.

Example: my mother-in-law’s hat

If the compound noun (e.g., brother-in-law) is to be made plural, form the plural first (brothers-in-law), and then use the apostrophe + s.

Example: my two brothers-in-law’s hats

Rule 4. If two people possess the same item, put the apostrophe + s after the second name only.

Example: Cesar and Maribel’s home is constructed of redwood.

However, if one of the joint owners is written as a pronoun, use the possessive form for both.

Incorrect: Maribel and my home

Correct: Maribel’s and my home

Incorrect: he and Maribel’s home

Incorrect: him and Maribel’s home

Correct: his and Maribel’s home

In cases of separate rather than joint possession, use the possessive form for both.

Examples:
Cesar’s and Maribel’s homes are both lovely.
They don’t own the homes jointly.

Cesar and Maribel’s homes are both lovely.
The homes belong to both of them.

Rule 5. Use an apostrophe with contractions. The apostrophe is placed where a letter or letters have been removed.

Examples: doesn’t, wouldn’t, it’s, can’t, you’ve, etc.

Incorrect: does’nt

Rule 6. There are various approaches to plurals for initials, capital letters, and numbers used as nouns.

Examples:
She consulted with three M.D.s.
She consulted with three M.D.’s.

Some write M.D.’s to give the s separation from the second period.

Many writers and editors prefer an apostrophe after single capital letters only:

Examples:
I made straight A’s.
He learned his ABCs.

There are different schools of thought about years and decades. The following examples are all in widespread use:

Examples:
the 1990s
the 1990’s
the ’90s
the 90’s

Awkward: the ’90’s

Rule 7. Amounts of time or money are sometimes used as possessive adjectives that require apostrophes.

Incorrect: three days leave

Correct: three days’ leave

Incorrect: my two cents worth

Correct: my two cents’ worth

Rule 8. The personal pronouns hers, ours, yours, theirs, its, whose, and oneself never take an apostrophe.

Example: Feed a horse grain. It’s better for its health.

Rule 9. When an apostrophe comes before a word or number, take care that it’s truly an apostrophe (’) rather than a single quotation mark (‘).

Incorrect:Twas the night before Christmas.

Correct: ’Twas the night before Christmas.

Incorrect: I voted in 08.

Correct: I voted in ’08.

NOTE

Serious writers avoid the word ‘til as an alternative to until. The correct word is till, which is many centuries older than until.

Rule 10. Beware of false possessives, which often occur with nouns ending in s. Don’t add apostrophes to noun-derived adjectives ending in s. Close analysis is the best guide.

Incorrect: We enjoyed the New Orleans’ cuisine.

In the preceding sentence, the word the makes no sense unless New Orleans is being used as an adjective to describe cuisine. In English, nouns frequently become adjectives. Adjectives rarely if ever take apostrophes.

Incorrect: I like that Beatles’ song.

Correct: I like that Beatles song.

Again, Beatles is an adjective, modifying song.

Incorrect: He’s a United States’ citizen.

Correct: He’s a United States citizen.

Rule 11. Beware of nouns ending in y; do not show possession by changing the y to -ies.

Correct: the company’s policy

Incorrect: the companies policy

Correct: three companies’ policies