English Punctuation Rules

Periods & Ellipses

1. Use the period after an indirect question.
2. If words are omitted at the end of a quoted sentence, use ellipses (three spaced periods, with one space before and after each period) followed by the necessary ending punctuation mark.
3. If sentences are omitted between other sentences within a quotation, use ellipses after the ending punctuation mark of the preceding sentence.
4. If the last word in the sentence ends in a period, do not follow it with another period.

Commas

1. To avoid confusion, use commas to separate words and word groups with a series of three or more.
2. Use a comma to separate two adjectives when the word "and" can be inserted between them.
3. Use a comma when an "-ly" adjective is used with other adjectives. Note that in order to test if an "-ly" word is an adjective, see if it can be used alone with the noun. If it can, use the comma.
4. Use commas to surround the name or title of a person directly addressed.
5. In case of dates:
  1. Use a comma to separate the day of the month from the year and after the year.
  2. If any part of the date is omitted, leave out the comma.
6. Use a comma to separate the city from the state and after the state.
7. Use commas to surround degrees or titles used with names.
8. Use commas to set off expressions that interrupt the flow of the sentence.
9. When starting a sentence with a weak clause, use a comma after it. Conversely, do not use a comma when the sentence starts with a strong clause followed by a weak clause.
10. Use a comma after phrases of more than three words that begin a sentence.
11. If something or someone is sufficiently identified, the description following it is considered non-essential and should be surrounded by commas.
12. Using a comma is optional to separate two sentences joined by a coordinating conjunction—"and", "or", "but", "for", "nor".
13. Use the comma to separate two sentences if it will help avoid confusion.
14. If the subject does not appear in front of the second verb, do not use a comma.
15. Use a comma to introduce or interrupt short direct quotations.
16. Use a comma to separate a statement from a question.
17. Use a comma to separate contrasting parts of a sentence.
18. Use a comma when beginning sentences with introductory words such as "well", "now", or "yes".

Semicolons

1. Use the semicolon in place of a period to separate two sentences where the conjunction has been left out.
2. Do not use a semicolon in front of words such as "therefore" and "however" if they do not connect two complete sentences or are used as interrupters.
3. Use a comma or a semicolon before introductory words such as "namely", "that is", "i.e.", "for example", "e.g.", or "for instance" when they are followed by a list of three or more items and preceded by a complete sentence.
4. If these introductory words are followed by fewer than three items, simply enclose them in commas.
5. Use the semicolon to avoid confusion where commas already exist.
  1. Use the semicolon to separate units of a series when one or more of the units contain commas.
  2. You may use a semicolon between two sentences that are joined by a conjunction but already have one or more commas within the first sentence.

Colons

1. Use the colon after a complete sentence to introduce a list of items when introductory words such as "namely", "for example", or "that is" do not appear. Skip two spaces after a colon.
2. Use the colon to introduce a list in tabular form whether it is preceded by a complete sentence or not.
3. Use the colon to introduce a direct quotation that is more than three typewritten lines in length. In this situation, single-space the long quotation and indent five spaces from each margin. Using quotation marks is optional.
4. Use the colon to follow the salutation of a business letter even when addressing someone by his/her first name. Never use a semicolon after a salutation. A comma is used after the salutation for personal correspondence.

Question Marks

1. Use a question mark only after a direct question.
2. Use a question mark when a sentence is half statement and half question.

Exclamation Marks

1. Use exclamation points to show emphasis or surprise. Do not use the exclamation point in formal business letters.

Quotation Marks

1. Periods and commas always go inside quotation marks, even inside single quotes.
2. The placement of question marks with quotes follows logic. If a question is in quotation marks, the question mark should be placed inside the quote.
3. When you have a question outside AND inside a quote, use only one question mark and place it inside the quotation mark.
4. Use single quotation marks for quotes within quotes. Note that the period goes inside all quote marks.
5. Use quotation marks to set off a direct quotation only.

Apostrophes

1. Use the apostrophe with contractions. The apostrophe is always placed at the spot where the letter(s) has been removed.
2. Use the apostrophe to show possession. Place the apostrophe before the "s" to show possession by one person.
3. To show possession by more than one person, make the noun plural first. Then immediately use the apostrophe.
4. To show singular possession with proper nouns ending in "s" or an "s" sound, you have the option of dropping the "s" that would normally follow the apostrophe.
5. With a singular compound noun, show possession with apostrophe and "s" (’s) at the end of the word as in Rule 2.
6. If the compound noun is plural, Rule 3 still applies.
7. Use the apostrophe and "s" after the second name only if two people possess the same item.
8. Never use an apostrophe with possessive pronouns—"his", "hers", "theirs", "ours", "yours". They already show possession and so do not need an apostrophe. The only time an apostrophe is used for "it’s" is when it is a contraction for "it is".
9. Using an apostrophe to show plurals of numbers, letters, and figures is optional.
10. Use possessive case in front of a gerund ("-ing" word).

Parentheses

1. Use parentheses to enclose words or figures that clarify or for an aside.
2. Use parentheses to enclose numbers of listed items in a sentence.
3. Periods go inside parentheses only if an entire sentence is inside the parentheses.

Hyphens

1. To check if a compound noun is two words, one word, or hyphenated, you must look it up in the dictionary. If you can’t find the word in the dictionary, treat the noun as separate words.
2. Phrases, which have verb and noun forms, should appear as separate words when used as verbs, and as one word when used as nouns.
3. Compound verbs are usually hyphenated or appear as one word. If you do not find the verb in the dictionary, hyphenate it.
4. Generally, hyphenate between two or more adjectives when they come before a noun and act as a single idea.
5. Remember to use a comma between two adjectives when you could have used "and" between them.

Hyphens with –ly Words

1. When the first word of the two-word modifier ends in "ly", hyphenate if the "-ly" word acts as one idea with the second word AND the "-ly" word can be used alone with the noun (i.e., the "-ly" word is an adjective).
2. When the word "and" can be inserted between the "-ly" word and the next adjective, use a comma between them.

Hyphens with Prefixes

1. The current trend is to do away with unnecessary hyphens. Therefore, attach prefixes and suffixes onto root words.
2. Hyphenate prefixes when they come before proper nouns.
3. Hyphenate prefixes ending in "a" or "i" only when the root word begins with an "a" or "i".
4. Double Es and double Os are usually made into one word. E.g.: reexamine, coordinate.
5. When a prefix ends in one vowel and a root word begins with a different vowel, generally attach them without a hyphen.
6. Hyphenate all words beginning with "self" except for "selfish" and "selfless".
7. Use a hyphen with the prefix "ex".

Hyphens with re- Words

1. Use the hyphen with the prefix "re" only when:
  1. the re means again, AND
  2. omitting the hyphen would cause confusion with another word.

Capitalization

1. Capitalize the first word of a quoted sentence.
2. Capitalize a proper noun.
3. It is often requested that you capitalize a person’s title when it precedes the name. Do not capitalize when the title is acting as a description following the name.
4. Capitalize when the person’s title follows the name on the address or signature line.
5. Capitalize the titles of high-ranking government officials when used with or without their names.
6. Capitalize points of the compass only when they refer to specific regions.
7. Capitalize titles of publications except for "a", "an", "the", "but", "as", "if", "and", "or", "nor", and other little words when used internally. Capitalize short verb forms like "Is", "Are", and "Be".
8. The capitalization rules for "state" and "federal" continue to be hotly debated. Capitalizing these words, when referring to them as agencies, is optional. When "state" and "federal" are actual parts of the agencies’ names, capitalize.
9. You may capitalize words such as "department", "bureau", and "office" if you have prepared your text in the following ways: “The Bureau of Land Management (Bureau) will have some jurisdiction over Fort Ord” or “The Bureau is finding this role difficult”.
10. Do not capitalize names of seasons.
11. Capitalize the first word of a salutation and the first word of a complimentary close.
12. Capitalize words derived from proper nouns.