A Super-Quick, Surprisingly Comprehensive Review of Basic Grammar

I created this quick grammar guide to help anyone who needs to express their ideas clearly in writing. Whether you’re a blogger, a CEO, or both, odds are you haven’t had a formal grammar lesson in a long time, and a little review can go a long way.

Pretty much every grammar rule I share here is curated from The Chicago Manual of Style (CMOS), a 956-page bible for grammar nerds. If you have any questions about the content presented here, get yourself a copy of the tome or subscribe to the online version. You’ll know you’re a true grammar nerd when that sounds like fun.

To make the most of this guide, my recommendation is to scroll through it to get a sense of the content, and then keep it handy. Maybe bookmark the page in your browser. Then, when someone asks if they should use e.g. or i.e., you can pull up the page, answer with confidence, and impress all your co-workers.

Let's get started.

Periods

Periods go at the end of sentences.

Commas

Commas are complicated, but if you follow these four basic rules you will, more often than not, put your commas in the right place.

Rule 1: Commas separate clauses in a sentence.

• Example: She loved Hawaii, but rarely took the time to vacation.

Rule 2: Commas set off the names of states.

• Example: San Francisco, California, is often foggy.

Rule 3: Commas separate items in a series.

• Example: His favorite colors are blue, green, and brown.

Rule 4: Commas are used with quotes.

• Example: “I’m planning to take some time off,” she said, “once I finish this project.”

Apostrophes

Like commas, four simple rules cover most of what you need to know.

Rule 1: Apostrophes can be used to show possession.

• Example of singular possessive: Bob’s hat fell to the floor. (apostrophe comes before the s)
• Example of plural possessive: The soldiers’ rifles were lined up in a row. (apostrophe comes after the s)

EXCEPTION: It’s = it is (the possessive form of it is “its”)

Rule 2: Apostrophes generally come at the end of a series.

• Example: We went to Jack and Donna’s house.

Rule 3: Apostrophes are used to shorten decades.

• Example: We have been there since the ‘70s.

Rule 4: Apostrophes are used to create contractions.

• Example: She is = she’s

Question Marks

Used for questions.

Example: Has Alex arrived?

Exclamation Marks

Used for exclamations and commands. Rarely called for in business writing.

Example: Wow!

Parentheses

Use these four basic rules.

Rule 1: Like a comma, parentheses can separate out incomplete clauses.

• Example: My favorite ice cream (chocolate mint) is the most popular flavor in the nation.

Rule 2: Parentheses can be used to include information that would not otherwise fit.

• Example: It wasn’t fully dark when we started walking (the sun had not set), but it was difficult to see.

Rule 3: Parentheses tend to de-emphasize.

Rule 4: Always consider whether the material should be another sentence.

Brackets

Rule 1: Use brackets when you are quoting someone and need to add words or phrases within quoted text for clarity.

• Example: “[Bob Jones] discovered a new element.” (Where [Bob Jones] replaces the “he” of the original quote.)

Rule 2: Use brackets instead of double parentheses.

Note: When you find yourself needing brackets inside parentheses, consider reorganizing.

En-dash

Joins numbers in a range. The en-dash should not be confused with the em-dash, which is slightly longer.

Minus Sign

Used to demonstrate a mathematical equation. It looks the same as an en-dash, but has spaces on either side.

Example: 5 - 3 = 2

Em-dash

Used like parentheses to pull out an independent phrase, but reserved for phrases of more importance. In most word processing programs, they are a special character. Note that they are about twice as wide as an en-dash.

Note: The em-dash tends to emphasize material, whereas parentheses de-emphasize.

Hyphens

Rule 1: Used to join two or more words that come before the noun they are intended to modify.

Rule 2: Used to tell the ages of people or things when the age is given before the noun.

Rule 3: Used to write out numbers under 100 and fractions

Quotation Marks

Rule 1: Quotation marks are used to denote that something was said.

Rule 2: Punctuation almost always goes inside quotation marks (for American English).

EXCEPTION: When the quote itself is not the question. Who said, “It is better to have loved and lost”?

Rule 3: If the words before a quote are any version of “to say,” you need a comma before the quote.

Semicolons

Rule 1: Semicolons separate complete sentences that are closely related.

Note: The word after the semicolon is not capitalized unless it is a proper noun.

Rule 2: Semicolons can be used in complex sentences where commas would be confusing.

Colons

Rule 1: Colons can be used after a phrase (of one word or more) to indicate that something more is coming.

Rule 2: Colons can be used to introduce a series of items. They should always be preceded by a complete sentence. When used accurately, they could be replaced with a comma and “namely.”

Rule 3: When a complete sentence comes after a colon, the first word in that sentence should be capitalized.

Ellipses (...)

Ellipses are used to show that a word or phrase has been deleted from a quoted passage.

Rule 1: Do not use ellipses before the first word of a quotation, even if the beginning of the original sentence has been omitted.

Rule 2: Do not use ellipses after the last word of a quotation, even if the end of the original sentence has been omitted.

Rule 3: The first word after ellipses points is capitalized if it starts a complete sentence, even if it was lowercase in the original.

Rule 4: We do use punctuation (including periods) before ellipses points, when they are needed for clarity. See the example for Rule 3.

Abbreviations

Acronyms : Do not use acronyms without fully identifying them first.

• Example: The North American Free Trade Agreement (NAFTA) dates back to 1994.

E.g. : The abbreviation “e.g.” is used in place of “for example.” It is not italicized and does require the use of a comma to set it apart from the text.

• Example: I like to play cards, e.g., hearts and crazy eights. (This sentence indicates that these are just two of the many games I like to play.)

Et cetera: Et cetera literally translates to “and other things” and is abbreviated with “etc.” It should not be used to refer to people. Do not use “and” before “etc.” Additional punctuation is not needed if it falls at the end of a sentence, but if you use it in the middle of a sentence, follow it with a comma.

• Example: The colors of the rainbow are red, orange, yellow, etc.
• Example: I brought my pencils, pens, etc., to the desk.

I.e. : The abbreviation “i.e.” is used in place of “in other words. It is not italicized and does require the use of a comma to set it apart from the text.

• Example: I like to play cards, i.e., hearts and crazy eights. (This sentence indicates that these are the only two games I like to play.)

Scholarly Degrees: Degrees are generally abbreviated without periods. When following a personal name, they are set off by commas.

• Example: Bob Cho received his BA from Duke University.
• Example: Katie Powers, JD, will visit the class.

States : In formal writing, the names of states and countries should always be spelled out. The exceptions are in addresses, and the “DC” in Washington DC.

Versus : The word “versus” indicates that two entities are opposed. It should be abbreviated with “vs.” In legal documents (i.e., in papers prepared by lawyers) it is usually abbreviated with “v.”

Formatting Numbers

Numbers 0-100 should be spelled out when used in text.

• Example: I have twenty-eight contractors.
• Example: We will need 132 computers.

Percentages: When the number is written out (as per the rule above), write out the word "percent" as well. When the numeral is used, use the percent symbol.

• Example: eight percent
• Example: 98%

Money: When writing out a dollar amount with numerals, include cents only if not equal to zero.

• Example: $1,200 (Incorrect: $1,200.00)
• Example: $570.54

When abbreviating a dollar amount written with numerals, it is acceptable to drop the zeros. Do not use “M” in place of the word “millions.”

• Example: $5 million (Incorrect: $5M)

Dates : Always write dates out (whether you include the year or not). Do not use ordinal indicators (such as “st,” “nd,” “rd”).

• Example: October 4, 2014 (Incorrect: October 4th, 2014 , 10/4/14 or 10/4/2014)

Times : Times should be written with numerals. Minutes should always been included after a colon. Include either a.m. or p.m. when needed for clarity. There should always be a space between the last number and either a.m. or p.m.

• Example: The meeting began at 9:00 a.m. and was done by noon.
• Example: Let’s meet at 10:30 a.m.

Note the lack of a second period in the example above. You need not double up on periods. However, if that example had been a question (Can you meet at 10:30 a.m.?) the question mark would be in addition to the periods used in the abbreviation (a.m.).

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Thanks for reading! I hope you enjoyed it and learned something useful from this little guide. If so leave a like and, as always, tips are hugely appreciated.