4Common mistakes

4.1U.S. versus British English

There are relatively few differences between U.S. and British English. Most differences are related to spelling (and pronunciation). Please consult the Merriam-Webster dictionary if unsure about a spelling.

U.S. English uses "s" and "z" (e.g., realize, organization, license, pretense) where British English uses "c" and "s".

U.S. English uses "o" where British English uses "ou". For example: "labor", "neighbor", or "favor".

U.S. English uses "e" where British English uses "ae" or "oe". For example: "anesthetic", "anemia", or "ameba".

U.S. English uses "er" where British English uses "re". For example: "center", "meter", or "theater".

U.S. English uses a double consonant in certain suffixes where British English uses a single consonant. For example, "travelling".

Avoid using words that do not mean the same thing in U.S. and British English, as well as slang terms.

4.2Serial or "Oxford" commas

Product Development, Financial, and Legal material. In a series of three or more terms with a single conjunction, use a serial comma (also known as the "Oxford" comma). For example:

The Norwegian flag is red, white, and blue.

Or:

My favorite combinations are green and yellow, blue and purple, and black and red.

Marcomm material. In a series of three or more terms with a single conjunction, the serial comma is used only in cases where a misunderstanding would result without it. For example:

The Norwegian flag is red, white and blue.

Or:

My favorite combinations are green and yellow, blue and purple, and black and red.

In the names of business firms, however, the serial comma will depend on how the company name is registered. Be sure to doublecheck the company's preference.

4.3Quick and dirty punctuation guidelines

Punctuation is used to clarify meaning and separate structural units. The guidelines presented here are arranged alphabetically by punctuation type.

Affixes. Pre– and suffixes are normally used without a hyphen. However, if a prefix (e.g., sub–, non–) is used to form a new word, the hyphen is used. For example:

non-persistent, sub-folder

Always use a hyphen when adding the prefix co– to words that start with "o" (for example, co-occur, co-official, co-organizer, co-owner), and when forming a new word.

Use a hyphen after the prefix re– to make distinctions between words that have different meanings. For example:

More information about hyphens can be found in the hyphens subsection.

Apostrophes. Use the normal possessive ending –'s after singular words or names that end in –s. This guideline also applies to plural possessives that do not end in –s. For example:

boss's, Jones's, children's, and Frenchmen's

Use the ending –s' on plural possessives that end in –s. This also applies to plural names that take a singular verb. For example:

Danes', bosses', Joneses', Barclays', and Stewarts & Lloyds'

Although singular in other respects, the United States, the United Nations, the Philippines, etc., have a plural possessive apostrophe. For example:

Who will be the United States' next president?

Do not use apostrophes when referring to decades. For example:

Opera Software was founded in the 1990s.

Colons. A colon is used chiefly to direct attention to something that follows, such as: a list, an explanation, or a quotation.

Commas. The abbreviations "i.e." and "e.g." are always followed by a comma, but should be used sparingly. The abbreviation "etc.", even if only a single term comes before it, is always preceded by a comma.

These cases can become complex quickly. Consult The Chicago Manual for more information on commas or contact the Language Services and Documentation team.

Hyphens. A hyphen is used especially to divide or to compound words, word elements, or numbers. As a general rule, compound nouns are written without a hyphen. For example:

home page, standards compliant, web browser, web master

But, there are exceptions (such as blood-money or bloodstream). A hyphen should generally be used when two or more words are used to modify a noun, and they precede the noun. For example:

home-page editor, standards-compliant browser, web-browser usage, web-master conference

A hyphen should be used before the word "based" when the modifier appears before the noun. For example:

Opera's latest standards-based release is getting good reviews.

This also applies to an adverb followed by an adjective, if used to describe something that follows. For example:

He asked a well-formed question.

Nouns and adjectives consisting of a verb phrase (verb + adverb) are never written as two words, are usually written with a hyphen, and sometimes are written as one word. For example:

built-in, dial-up, feedback

Semicolons. A semicolon is used chiefly in a coordinating function between major sentence elements; major sentence elements are independent clauses of a compound sentence.

In most cases, these clauses can be split into two sentences. If the clauses are closely related–if they clarify each other and deal with the same explicit subject matter–you may consider using a semicolon.

4.4Common abbreviations

Exert care when using abbreviations. Latin abbreviations should be avoided, especially in formal writing. They are okay to use within parenthetical material, or in tables or other cases where space is at a premium, however. Remember to use a comma after "i.e." or "e.g.".

The following table contains a list of a common abbreviations and their meanings:

Use the abbreviation "v." to stand in place of "versus" when writing about court cases. For example, Brown v. Board of Education.

Uncommon or esoteric abbreviations should be used sparingly, and only after you have fully defined the term at least once in preceding text.

To maintain a professional image and clear, concise writing standards, the following abbreviations should never be used:

• Words such as "through" (thru), "night" (nite), and "to be" (2B)
• Days of the week or months of the year (in the normal flow of text)
• Words at the beginning of a sentence
• People's names such as Chas. (for Charles) or Jas. (for James), unless those abbreviations have come to be accepted as nicknames for those particular individuals
• States' names such as Mass. (for Massachusetts) or Conn. (for Connecticut), except when appropriate (as in datelines for press releases or the addresses for envelopes), or when the AP Stylebook or U.S. Postal Service's approved two-letter abbreviations (for instance, MA or CT, without periods) must be used, respectively
• Course names such as "Econ" (for Economics) or "Poli Sci" (for Political Science)

4.5Restrictive and nonrestrictive clauses

Restrictive clauses. A restrictive clause is a descriptive clause that is essential to the meaning of the word it modifies. If a word or phrase has a restrictive function (i.e., modifies a noun), it is not set off by commas because if the clause were removed the essential meaning of the sentence would change.

It is recommended that you use "that" to set up restrictive clauses. For example:

All employees that wish to donate blood may take Thursday afternoon off.

Nonrestrictive clauses. A nonrestrictive clause, always set off by commas, provides additional information about the noun it modifies; however, it may be omitted without changing the meaning of the sentence.

A word or a phrase that restates a noun or pronoun in different words is a nonrestrictive clause. If you state that "your wife, Nora, took you to dinner last night," either "your wife" or "Nora" could be eliminated without changing the meaning. Writing that "your wife Nora took you to dinner" implies that you have more than one wife and that you are referring to the one named Nora. Thus, the clause becomes restrictive.

It is recommended that you use "which" to set apart nonrestrictive clauses. For example:

Opera browser, which is a standards-compliant browser, supports most HTML5 elements.

4.6Commonly misused words

U.S. English can be tricky. Words sometimes sound the same but have different spellings, or are spelled the same but have different meanings. This list contains commonly misused words, their part of speech, and their correct usage.

affect

1 : to influence; to cause a response. For example, "This guide will affect my thinking."

2 : to assume; to be given to; to pretend. For example, "She affected a silly manner of speaking."

effect

a result or accomplishment. For example, "What was the effect of this appealing guide?"

effect

to cause; to bring about. For example, "The new rendering engine will effect major changes in our DOM support."

effects

goods; property. For example, "The deceased man's effects were willed to charity."

its

that which belongs to it or itself. For example, "The dog bit its tail."

it's

it is; it has. For example, "It's clear to me now how it's become such a common mistake."

lay

to set down; to put or place someone or something in a horizontal position.

'Lay' is a transitive verb, requiring a direct object that receives the action of the verb.

present	He lays the rug on the floor.
present progressive	He is laying wallpaper.
past	She laid her manuscript on the table.
past perfect	The storm had laid the grain flat.

lie

to rest; to recline; to be in a prostrate position.

'Lie' is an intransitive verb and takes no object.

present	My dog lies on the guest bed.
present progressive	The pen is lying on the desk.
past	I lay down yesterday.
past perfect	I have lain down every day this week.

U.S.

an abbreviation used only as a modifier. For example, "Obama spoke about U.S. foreign policy."

In informal writing, "U.S." is often incorrectly used as a noun to refer to the United States.

"U.S." should always be written with the periods, unless it is appearing in a headline, per AP style.

USA

an abbreviation referring to the United States of America. For example, "Albuquerque is a city in the USA."

In Opera documents, 'the USA' or 'the United States' must be used to refer to the United States of America.

'USA' may be used in parenthetical references when space is a consideration. This happens most often in financial material.

your

objects associated with you, yourself, or yourselves. For example, "Your contributions to this guide were important."

yours

that which belongs to you and only you. For example, "This guide is yours."

you're

you are. For example, "You're reading this guide."