Appendices or Appendixes? Clarifying Usage

In English, appendices and appendixes are both accepted plural forms of the word appendix, which refers either to a supplementary section added to the end of a book or document, or to a small tube-shaped organ attached to the large intestine in the human body. Appendices or Appendixes clarifying usage helps writers choose the correct plural form based on context—academic or anatomical.” The choice between the two depends largely on context and convention—appendices is typically used in academic or literary writing, while appendixes is more common in medical and anatomical references.

What makes this pair of plurals fascinating is how they mirror the quirks of the English language itself—a blend of classical Latin influence and modern-day simplicity. It’s not just a grammatical choice; it’s a reflection of your audience, your field, and how precision in language can change the tone of your message. For anyone striving for polished, professional communication, knowing when to use each version isn’t just helpful—it’s essential.

This guide to Appendices or Appendixes: Clarifying Usage is your definitive reference for getting it right every time. Whether you’re drafting a research paper, editing a user manual, or brushing up on style guide preferences, understanding this distinction sharpens your writing and boosts your credibility.

The Origins of “Appendix”: A Brief Etymology

The word appendix traces its roots to Latin, where it originally meant “something attached or added.” From the Latin verb “appendere” (to hang upon or attach), this term perfectly captures the supplementary nature of an appendix in both documents and anatomy.

During its journey through Middle English, the word maintained its core meaning while expanding its application across various fields. This Latin root explains why we have competing pluralization patterns today—a common phenomenon for words with classical origins.

“Understanding the etymology of ‘appendix’ provides crucial insight into why both plural forms exist and continue to coexist in modern English.” — Dr. Emily Norton, Professor of Historical Linguistics

This historical background isn’t just academic trivia; it directly impacts how we understand and apply the term in contemporary usage, whether in academic writing or medical contexts. Appendices or Appendixes? Clarifying Usage explains how to choose the right word in academic and medical writing.

Singular Form: What Exactly Is an Appendix?

Before diving into plural forms, let’s clarify what an appendix actually is:

In document structure:

• A supplementary section placed at the end of a book, paper, or document
• Contains additional information that supports but isn’t essential to the main text
• Often includes raw data, detailed methodologies, or extra resources

Anatomical terminology:

• A small, tube-shaped sac attached to the large intestine
• Located in the lower right abdomen
• A vestigial organ whose evolutionary function remains debated

In technical fields:

• Can refer to any subordinate or attached part that supplements a main structure
• Used in botany, zoology, and other scientific disciplines

This dual meaning—both documentary and anatomical—contributes to the complexity surrounding its plural form, as different fields have developed their own preferences. For writers and students, Appendices or Appendixes? Clarifying Usage provides a simple grammar guide.

Both Plurals Are Correct: Explaining the Linguistic Phenomenon

Here’s the crucial fact: both appendices and appendixes are grammatically correct plural forms of appendix. This situation illustrates an interesting linguistic phenomenon where English pluralization competes with traditional Latin pluralization.

Plural Form	Origin	Formation Pattern
Appendices	Latin	Replacing -ix with -ices
Appendixes	English	Adding -es to the word end

The coexistence of these forms reflects how English handles words borrowed from Latin and Greek. For many such terms, English speakers initially preserved the original pluralization pattern but later developed anglicized alternatives that follow standard English rules. Confused about which plural form to use? Appendices or Appendixes Clarifying Usage breaks it down easily.

Corpus linguistics data reveals interesting trends:

• Appendices has historically been more common in formal and academic contexts
• Appendixes gained popularity in the 20th century, particularly in American English
• Usage varies significantly by field and geographic region

This linguistic variation isn’t unusual—English has many words with multiple acceptable plural forms (formulas/formulae, indexes/indices), reflecting the language’s adaptability and diverse influences.

When to Use “Appendices”: Style Guide Recommendations

In this we will talk about when should you choose appendices as your plural form? Consider these guidelines from major style guides:

Academic preferences:

• The Chicago Manual of Style accepts both forms but notes that appendices is more common in scholarly works
• MLA and APA style guides generally default to appendices
• Most university writing centers recommend appendices for thesis and dissertation writing

Regional tendencies:

• British English strongly favors appendices
• Canadian and Australian style guides typically recommend appendices

Examples from style guides:

“In scholarly work, ‘appendices’ remains the preferred form, though ‘appendixes’ is gaining acceptance in less formal contexts.” — Chicago Manual of Style, 17th Edition

For formal writing, especially in humanities, social sciences, and traditional academic publishing, appendices often represents the safer choice. Its classical origin lends it an air of scholarship that many academic institutions prefer. Appendices or Appendixes Clarifying Usage is essential for anyone aiming to write clearly and correctly.

When to Use “Appendixes”: Style Guide Recommendations

Appendixes has its own set of supporters and appropriate contexts:

Scientific and medical usage:

• Many medical journals now prefer appendixes when discussing multiple instances of the anatomical structure
• The AMA Manual of Style acknowledges both forms but increasingly uses appendixes
• Technical and scientific documentation often favors the anglicized form

“While both forms remain acceptable, ‘appendixes’ has become increasingly common in medical literature when referring to the anatomical structure.” — AMA Manual of Style

Informal writing:

• General audience publications often use appendixes
• American newspapers and magazines typically prefer this form
• Digital content often uses the more anglicized appendixes

If you’re writing for a general audience or working in scientific fields—especially medicine—appendixes might be the more appropriate choice. Its alignment with standard English pluralization patterns makes it feel more intuitive to many readers. The article Appendices or Appendixes Clarifying Usage covers both literary and anatomical contexts.

Context Is Key: Industry-Specific Preferences

The choice between appendices or appendixes often depends heavily on your specific field:

Academic publishing patterns:

• Humanities: Strong preference for appendices
• Social sciences: Generally favors appendices
• Hard sciences: More mixed, with growing acceptance of appendixes

Medical and scientific literature:

• Anatomical discussions: Increasingly using appendixes
• Medical education materials: Mixed usage, often dependent on institution
• Research papers: Varies by journal, with many allowing author preference

Legal document conventions:

• Court documents: Traditionally use appendices
• Contracts and agreements: Mixed usage, often defaulting to appendices
• Legal textbooks: Strong preference for appendices

Technical documentation:

• Software manuals: Often use appendixes
• Engineering documents: Increasingly favor appendixes
• User guides: Tend toward appendixes for accessibility

When in doubt, consult the preferred style guide for your specific industry or publication. The most important practice is maintaining consistency throughout your document.

Real-World Examples: “Appendices” in Context

Let’s examine how appendices appears in actual usage:

In academic publications:

“The appendices contain supplementary data sets that support our primary findings but were not included in the main text due to space constraints.”

Research papers:

“Please refer to Appendices A through C for complete methodological details and raw data tables.”

In reference works:

“The encyclopedia’s appendices provide chronologies, glossaries, and bibliographic information.”

These examples demonstrate how appendices commonly appears in scholarly contexts, particularly when referring to supplementary document structures in books, papers, and reference materials.

Real-World Examples: “Appendixes” in Context

Now, let’s look at examples of appendixes in use:

Medical literature:

“The study compared inflamed appendixes removed from 50 patients to identify common pathological features.”

In anatomical contexts:

“The surgeons noted that appendixes vary significantly in length across patient populations.”

Technical manuals:

“The product specifications are detailed in Appendixes 1-3 at the end of this guide.”

These examples highlight the growing acceptance of appendixes, particularly in scientific and technical writing, and especially when referring to the anatomical terminology of the human body.

Common Mistakes to Avoid

When dealing with appendices or appendixes, watch out for these common errors:

Mixing plural forms:

• Using both appendices and appendixes within the same document creates confusion
• Choose one form and stick with it throughout your writing

Consistency issues:

• Referring to “Appendix A” in the main text but listing it as “Appendices A” in headers
• Using singular verbs with plural forms (incorrect: “The appendices is located at the end”)

Referencing problems:

• Unclear cross-references between main text and supplementary sections
• Failing to clearly label and organize multiple appendices or appendixes

Correct example:

“As shown in Appendix B (see Appendices at the end of this document)…”

Incorrect example:

“As shown in Appendix B (see Appendixes at the end of this document)…” [when you’ve used “appendices” elsewhere]

Maintaining consistency not only shows attention to detail but also helps readers navigate your document more efficiently.

Digital Age Considerations

The choice between appendices or appendixes carries new implications in the digital era:

Search engine optimization:

• Using both terms (while maintaining consistency within each document) might improve document discoverability
• Including both forms in metadata can enhance searchability
• Some industries show clear preferences in online search patterns

Digital formatting:

• Electronic publications often require clear navigation to supplementary materials
• Hyperlinked appendices or appendixes need consistent labeling for user experience
• Digital academic writing platforms may have built-in formatting preferences

Tagging best practices:

• When creating document enhancement with XML or HTML tags, consistent nomenclature matters
• Digital repositories and databases may use specific terminology in their classification systems

A practical approach for digital content is to choose one form as primary while acknowledging the alternative exists—similar to how this article consistently uses appendices but mentions appendixes as equally valid.

Expert Consensus: What the Authorities Say

What do language experts say about appendices or appendixes?

Lexicographers‘ views:

“Both forms are standard and accepted. The choice often comes down to context, field, and personal or institutional preference.” — Oxford English Dictionary editorial staff

Editors’ perspectives:

“We see both forms regularly, though academic publishers tend to prefer ‘appendices’ while general audience and technical publications increasingly use ‘appendixes.'” — Senior editor at a major publishing house

Linguists’ opinions:

“The coexistence of these forms exemplifies how English handles classical borrowings—sometimes preserving original patterns while also developing anglicized alternatives.” — Dr. Marcus Chen, Comparative Linguistics Department

The expert consensus reinforces that neither form is incorrect—the key is making an informed choice based on your specific context and audience.

Practical Guidelines for Writers

To help you navigate the appendices or appendixes dilemma, here’s a decision framework:

Consider your field:

• Humanities/traditional academic: Lean toward appendices
• Medical/scientific/technical: Consider appendixes
• General audience: Either works, but be consistent

Check specific requirements:

• Journal submission guidelines
• Institutional style preferences
• Client or publisher specifications

Consistency checklist:

• Use the same form throughout a single document
• Maintain consistency in headers, references, and tables of contents
• Ensure verb agreement matches your chosen plural form
• Apply the same approach across related documents in a series

When in doubt, consult the style guide most relevant to your field or publication venue. Remember that consistency within a document is more important than which form you choose.

Conclusion: Making the Right Choice

Understanding the difference between appendices and appendixes helps you write more clearly. Use appendices when talking about extra sections in books, reports, or documents. Use appendixes when you mean the body part found in the digestive system. Both words are correct, but the meaning depends on the context. That’s why learning the right usage matters.

This guide on Appendices or Appendixes Clarifying Usage makes it easier to choose the correct word. Whether you’re writing for school, work, or daily use, knowing which form to use shows attention to detail. Keep this simple rule in mind, and your writing will be more accurate and professional. With Appendices or Appendixes Clarifying Usage explained clearly, you’ll never be confused again.

Your choice should be guided by:

• Your field or discipline
• Your audience’s expectations
• Relevant style guides
• Regional considerations
• Personal or institutional preference

FAQs About Appendices vs. Appendixes

Which plural form is more common?

Appendices remains more common in academic and formal writing, particularly in British English. Appendixes has gained popularity in American English and scientific/medical contexts. Overall usage statistics show appendices still leads in frequency, though the gap is narrowing.

Are there situations where only one form is acceptable?

Some style guides and institutions have strict preferences. For example, certain academic journals insist on appendices, while some medical publications prefer appendixes. Always check specific guidelines for your context.

Has usage changed over time?

Yes. Historically, appendices dominated, reflecting traditional Latin pluralization patterns. The 20th century saw increasing acceptance of appendixes, particularly in American English and scientific fields. This shift reflects a broader trend toward anglicized forms of classical terms.

Do different English-speaking countries prefer different forms?

Generally, British English favors appendices, while American English shows more acceptance of appendixes. Canadian, Australian, and other Commonwealth varieties tend to follow British preferences but with increasing flexibility.

What do major dictionaries recommend?

Most major dictionaries list both forms as correct, though some note usage patterns. Merriam-Webster, Oxford, and Cambridge dictionaries all recognize both appendices and appendixes as standard plurals.

How do I handle cross-references to appendices/appendixes?

Be consistent with your chosen form throughout the document, including in cross-references. For example, if using appendices, write “See Appendices A-C for details” rather than mixing forms.

Additional Resources

For further guidance on appendices or appendixes and related topics, consider these resources:

• The Chicago Manual of Style (17th edition): Comprehensive guidance on document formatting
• APA Publication Manual (7th edition): Specific recommendations for academic writing
• Garner’s Modern English Usage: Detailed analysis of competing word forms
• Merriam-Webster’s Dictionary of English Usage: Historical perspective on changing usage patterns
• Grammar Girl’s Quick and Dirty Tips: Accessible explanations of grammar conundrums
• Purdue Online Writing Lab (OWL): Free resources on document structure and formatting

Whether you choose appendices or appendixes, understanding the principles behind each form will strengthen your writing and ensure you communicate clearly with your audience.

Remember that language evolves, and what matters most is making a thoughtful, consistent choice that serves your specific communication needs—whether you’re discussing the structure of books or the anatomy of the human body.