Breaking it Down: An Introduction to APA Capitalization Rules -->

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Breaking it Down: An Introduction to APA Capitalization Rules

APA rules can sometimes be confusing, including rules about capitalization.  Despite slight variations, the main capitalization rules can be broken down into two format categories: title case and sentence case.

Title case is when you capitalize the first letter of all words that are 4 or more letters long:

·         Title of Your Paper
·         Level 1 Section Headings
·         Level 2 Section Headings
·         References Title
·         Table titles
·         Appendices titles  

There aren’t as many rules for the title case in APA, simply because most capitalization rules will focus on the second category of rules: The sentence case.

Sentence case follows standard sentence capitalization rules where capitalization is used only for the first letter of the first word, proper nouns, and the first word after a colon:

·         Sentences within your paper
·         Level 3 headings
·         Level 4 headings
·         Figure titles
·         Titles of sources in APA-style reference entries

Let’s take a closer look at the sentence case rules as they relate to the sentences in your paper. After explaining the rule and providing an example, I will also share with you two contrary rules that exist in special circumstances. Let’s face it, the longer you learn about APA style, the more contrary rules you will find. 

The first letter of the first word
The first letter of the first word after a colon
Proper nouns (including trade names and specific titles)
Nouns followed by numerals (because they refer to specific “things”)

The color-code corresponds to the matching portion of the example sample: 

Example: According to the American Psychological Association (APA, 2010), writers need to “Capitalize nouns followed by numerals or letters that denote a specific place on a numbered series” (103). Here is one example provided: “On Day 2 of Experiment 4” (103).

And as usual, there are some exceptions to the rule.

Contrary rule #1: Titles of written works (such as books and article titles), follow title case rules as well as  “Capitaliz[ing] all verbs (including linking verbs), nouns, adjectives, adverbs, and pronouns” (APA, 2010, p. 101).

Example: In her book, Scholars’ Attitudes About Learning Styles…
When you are referring to the title of a source in the sentences of your paper, make sure you capitalize. Unless, of course your subject is related to the next contrary rule.

Contrary Rule #2: “Do not capitalize the names of laws, theories, models, statistical procedures, or hypotheses” (APA, 2010, p.102) since they can be understood to serve more as common nouns as opposed to proper nouns.

Example: Maslow’s (1943) hierarchy of needs
Example: According to the classical conditioning model, …….(Watson, 1924)

There are, of course, other capitalization rules. Aside from the Writing Center’s overview of capitalization rules, and the APA style blog, students can also find a breakdown of the rules with examples in the APA Manual (6th ed.), on pp. 101-104 (or 4.14-4.20).

We also have an interactive lesson on capitalization on our website. Make some time to take our APA capitalization quiz and let us know how you did in the comments below.  

Veronica Oliver 
is a Writing Instructor in the Walden Writing Center. In her spare time she writes fiction, binge watches Netflix, and occasionally makes it to a 6am Bikram Yoga class.

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  1. Dear Veronica Oliver,
    Thank you for educating me about APA use in writing. I have actually seen and observed critically the mistakes I have been making. This time round I will be a good writer. I have come to learn that writers need to capitalize nouns followed by numerals or letters that donate a specific place on a numbered series.
    Also I didn't know that titles of written works follow case rules as well as capitalizing all verbs, nouns, adjectives, adverb, and pronouns.

    Please, I need to learn a lot from you on an interval of two days week in week out.

    1. Thank you for your post, Horace. We are thrilled that this post was helpful to you. I encourage you to check out more about capitalization on our website:

  2. What about the names of different subjects? English language asks for not capitalizing the subject names unless it is a language subject..
    What do we do in APA format?

    1. We still follow that rule! For example, "English" as a subject will be capitalized because it's also the proper name of a language. The subject "science", however, is left lowercase because it is not a proper name. Now sometimes these words make their way into proper names or organizations or programs, and then we would capitalize them. For example, American Science Center.