You might have learned many black and white versions of English. Being a professional student or a writer you might be aware of English style guides. There are many styles that English follows and each of them serves a specific purpose. Many people are familiar with APA or MLA style which we are not addressing in this article. We would not discuss The Gregg Reference Manual that is renowned for business manuscripts neither we would cover the British style Oxford.

In this article we would draw the comparison between two American style guides

  1. The Chicago Manual of Style.
  2. AP Stylebook.

Six categories of these styles would be compared that includes; punctuation, capitalization, numbers, abbreviations, spellings and particular words and their formats. But before that we need to understand the way in which you can empower your grasp onto the concepts of style guides and good English.


Chicago Manual of style is famous among the writers. Since 1906 the style has also been used for literature so some students might be familiar with the style. The AP stylebook is considered to be the bible of journalists it was issued in 1953. The style emphasize on space saving and most of the web content is based upon this style.

In 2017 the seventh edition of The Chicago Manual of style was issued. Here in this particular article we will highlight the important updates made in Chicago Manual of Style and its comparison with the AP stylebook along with the updates made recently in AP Stylebook.


The point to ponder here is that these are not style rules rather they are style guides. To produce an excellent quality of text you must be consistent. There is also a dire need to be consistent around website content and etc. But being consistent does not mean that you can never break the rule, rules can be broken sometimes by using a least common form such as a passive voice.


When it comes to reading content from web you get to see different versions of English. These versions are different from each other in terms of vocabulary, grammar, expressions, punctuations and etc. You will also see a difference between the writing of different writers who write in the same language English but are different in terms of the content and the type of the language they produce.

What develops this difference? Well this difference is developed when there are some people who has English as their first language and some who has not acquired English rather learned it as a second language because there would be some errors as their proficiency in the language would not be as much as it is of a native speaker’s and that will reflect in their writing also.

When you read a content produced by the company itself it may be a brand, an industry or etc. you will notice that apart from the jargon they use they also omit some rules. Being a professional writer you would not need to seek anyone else’s guidance regarding proper use of English. However for proofreading and editing you might knock at someone's door because even the professionally written can have mistakes and errors in them.

Now let’s draw the comparison between the two of these style guides:




AP' 17


(The instructions given in both CMOS and AP Style are so lengthy you need to look for the details in your style guide)

Use serial comma to represent each item to maintain clarity.


I bought apples, mangoes, and kiwis.

Serial comma is omitted in a simple sentence.


I bought apples, mangoes and kiwis.

Serial comma is used in a complex series to make it clear.


I bought apples, mangoes, and

 Kiwis and pineapples.

Etc/and so forth/and the like

Comma is not applied after the following terms unless it is a grammatical requirement.

Example (without comma)

New shoes, clothes, jewelry, etc. makes me happy.

Example (with comma)

New shoes, clothes, jewelry, etc., make me happy.

AP style suggests using the comma in all situations.


New shoes, clothes, jewelry, etc., make me happy.


Unless the word is at the end of a sentence, comma is not applied before the word either.


I like fruits too.

I don't like much fruits either.

In case of coordinating conjunction i.e. but, and, or, etc. Depends upon the sentence structure.

If the conjunction completes sentences, the comma is applied before the conjunction.

Commas are used to develop clarity.

I like fruits too 


I don't like books much, either fiction or non-fiction and science fiction.

Participial or adverbial phrase plus conjunction

The words that follow a conjunction if do not make a complete sentence, then the comma is applied after the conjunction.

Example (before conjunction)

I was sad, but because they came over, I was also happy.

(I was sad, but.....I was also happy)

Example (after conjunction)

I was sad but, having them there, also happy.

(I was sad but....also happy)

AP style gives no particular guidelines regarding this.





AP' 17

Capitalization, general 

(Note: capitalization has been discussed at length in both the styles so you need to refer to the style guide for thorough instructions)


AP style suggests avoiding unwanted capitalizations. Capitalize an abbreviation only if it’s a proper noun otherwise capitalization is not required.



National Aeronautic Space Administration.


as soon as possible

Mid-sentence, or interpolated, questions.

CMOS recommend the capitalization of a question that is a part of a sentence without putting quotation marks around it.


She said, Are you mad?

AP style suggests the same as CMOS.

Bulleted lists

Those items that are not complete sentences may or may not be capitalized, but they remain consistent.

AP style suggests capitalizing the first word of bulleted list and closing it with a full stop. 

(Note: for true news stories dashes are used as a substitute to bullets; in web content however the bullets are preferred).

Oxford shoes/ Chelsea boots


Capitalize the word that is modifying the noun.


The Oxford shoes.

Oxford is the modifier.

Generation X/ Generation Y/ Generation Z

Use a capital G

Use a capital G

Romantic and Romanticism

Use a capital R.

romantic and romanticism with a lower case r

Romantic Movement with an uppercase R.


Lowercase because uppercase letters would be preferred in a situation when there is a proper noun.

Prefer lowercase internet.

Unusual capitalization of company names, brand names, and trademarks.

I shop from Amazon.

I use Asap whitening cream.

Since Asap is a brand that’s why it’s been capitalized.

No particular guidelines are given except of this that capitalizes the brand names if it’s necessary.





AP' 17

Numbers, general

(Note: since the instructions are quite lengthy you need to follow the style guides for complete guidelines)

CMOS refers to the method to spell out the numbers from 'zero' to 'one hundred'. However large round numbers are written as it is.


I saw ninety-eight kites.

AP recommends writing the numerals from 0 to 100.

There were 80 kites.

US phone numbers

Please call (1-800) 444-1313.


Please call 1-800-444-1313

AP suggests using the format in second language only.

Please call 1-800-444-1313

Twenty-four-hour time

A colon is used to make it clear 


The class is at 05:00 p.m.


Super Bowl

CMOS prefers the Arabic numerals over the Roman ones.

AP style prefers not to use the Roman numerals.


The match was won in 1992.





You can refer to the United States by omitting a period, as a noun and also as an adjective.


The novel was published in US.

AP style suggests using a period U.S. to state it as a noun or an adjective specifically in the news.


The president visited U.S. last week.


CMOS prefer the spelling out of the names of months when there is enough space.





AP style prefers the abbreviations when there a date is combined with a month.

1st Jan

2nd Feb


Spelling and specific words


spelling, general

Words that are not served in CMOS can be found in Webster's Third new international dictionary or Merriam Webster's collegiate dictionary

The words that are not used in AP style can be found from Webster’s new world college dictionary.


Email is not written with a hyphen like e-mail rather without it.

Email written without a hyphen.


It is written with hyphen always when used as a noun and an adjective.


He has got decision-making skills.

AP or Webster's dictionary has not specified whether it should be written with a hyphen or not.


These pronouns are in the process of transformation. It has been discouraged by the CMOS to use these pronouns in formal writing. Recast these sentences to omit problems.


The students should not use their mobile phones in the class rooms.


The students may not use the mobile phones in the class rooms.

AP style recommends using these singular pronouns when you need to save someone's name.


The students should know what they are supposed to do.


The topic is not treated in the text rather it is discussed in the forums. It would be preferable to follow AP style in this regard.

It has got changed from the hyphenated version Wal-Mart.


There is no particular entry.

The term used to refer to multi-player games.


According to Merriam Webster dictionary flier is associated with air traveling and flyer is with advertising.

Transformed from flier to flyer.

Virtual reality


Abbreviation VR to be used as alternative.



Addiction word should not be associated to a trouble, abuse or being alcoholic rather it is a disease.



Both of these terms can be used.

Same-sex marriage


It can be used as an alternative to gay marriage.

Versus/ vs./v.

In CMOS versus the full form is used in writings mostly. Vs. is used for headlines and v. for court documents.

AP style follows the same rule as CMOS.



The word has no hyphen to divide it into two.




Italicized words are only used when they are from the standard English dictionary otherwise foreign words will not be italicized.


He greeted me saying hola.


English men say hello.

No particular rules are set for English dictionary words rather foreign words are prescribed to be marked with quotation marks.

Bon appetite!


The French soldier said "bonjour," or good day.

Emphasizing text

Italicized words should be used in formal writing and printed manuscripts. All words should not be capitalized in formal writing.

AP involves Roman style in news stories only. However the capitalized forms are for headlines and other instances only.



Since both of these style guides lengthy so we prescribe you to buy their copy or get them online.