When it comes to writing, even small words can trip you up. One of the most common questions writers face is:
should I write “appendices” or “appendixes”? Both are technically correct, but knowing which one to use in different contexts can make your writing sharper and more professional.
Appendices or AppendixesIn this guide, we’ll break down everything you need to know about the singular and plural forms of appendix, their history, usage, and tips for avoiding mistakes.
Understanding the Word “Appendix”
At its core, the word appendix comes from the Latin “appendere,” meaning to hang upon. In English, it carries two main meanings:
- Textual or academic: Extra material added at the end of a book, research paper, or document.
- Anatomical: A small organ attached to the large intestine, commonly referred to in medical contexts.
Understanding which appendix you’re talking about will guide whether you use appendices or appendixes.
Singular Form of Appendix
The singular form is always appendix.
- In books or documents:
- “The appendix at the end of the report contains supporting graphs.”
- In anatomy:
- “The patient’s appendix was inflamed and required surgery.”
Notice how the singular form works seamlessly in both contexts. Problems arise when we try to pluralize it.
Plural Forms: Appendices vs. Appendixes
English can be tricky because it borrows heavily from Latin. This is why appendix has two acceptable plural forms.
Classical (Latin) Plural: Appendices
- Derived directly from Latin, “appendices” is the plural of “appendix.”
- Preferred in formal, academic, or technical writing.
- Example:
- “The book includes three appendices detailing the survey results.”
Modern English Plural: Appendixes
- A more Anglicized version of the plural.
- Acceptable in informal writing, general English, and everyday usage.
- Example:
- “The report’s appendixes summarize the main findings in simpler terms.”
Comparison Table: Appendices vs. Appendixes
| Feature | Appendices | Appendixes |
|---|---|---|
| Origin | Latin | English adaptation |
| Context | Formal, academic, technical | Informal, casual, general |
| Usage in anatomy | Acceptable | Acceptable, less common |
| Example | “Refer to the appendices for more data.” | “The appendixes list all attachments.” |
When to Use Each Plural Form
Choosing the right plural depends on your audience and the context:
Use Appendices When:
- Writing academic papers, books, or research articles
- Formal professional reports
- Following style guides like APA, Chicago, or MLA
Use Appendixes When:
- Writing informal content or blogs
- Creating casual reports or memos
- Talking in general terms outside of academic settings
Example in context:
- Academic: “All appendices have been reviewed by the research committee.”
- Informal: “Check the appendixes at the end for extra tips.”
Appendix in Different Fields
Books and Documents
- An appendix provides additional information, charts, tables, or explanations.
- Often labeled with letters (Appendix A, Appendix B) or numbers (Appendix 1, 2).
- Adds credibility and depth without cluttering the main text.
Anatomy
- The appendix is a small tube attached to the large intestine.
- Pluralization here can differ slightly: medical texts sometimes prefer appendices when referring to multiple anatomical structures, but appendixes is still acceptable in general English.
- Example: “The surgeon removed two appendices from the cadaver during the dissection.”
Etymology and History of “Appendix”
- Origin: Latin appendere → to hang upon or attach
- First usage in English: 15th century
- Textual meaning: Added in books since the 16th century
- Anatomical meaning: Commonly used in medical literature by the 18th century
Timeline of Usage
| Year | Context | Usage Example |
|---|---|---|
| 1500s | Books & texts | “See the appendix for further references.” |
| 1700s | Anatomy | “The appendix is inflamed in this specimen.” |
| 1800s-1900s | Academic writing | “All appendices are formatted according to style guides.” |
| 2000s+ | Modern English | “Appendixes provide extra context in informal reports.” |
Examples in Context
Appendix (Singular)
- “The appendix includes additional charts for clarity.”
Appendices (Plural, academic/formal)
- “The report’s appendices show detailed survey results.”
Appendices (Plural, anatomy)
- “During the autopsy, both appendices were examined carefully.”
Appendixes (Plural, informal/general)
- “The appendixes at the end of the manual summarize all safety protocols.”
Regional and Style Preferences
- American English: Both forms are acceptable; “appendices” is slightly more formal.
- British English: “Appendices” is preferred in academic writing; “appendixes” is rare but understandable.
- Style Guides:
- APA → Appendices
- Chicago → Appendices for formal, Appendixes acceptable for informal
- MLA → Appendices
This means knowing your audience and following your chosen style guide can prevent small but noticeable mistakes.
Common Mistakes to Avoid
- Confusing appendices with other plural words ending in -ix (like matrix → matrices)
- Using “appendixes” in highly formal academic papers—usually flagged by editors
- Forgetting to label appendices in books or reports properly
FAQs About Appendices or Appendixes
Is one form more correct than the other?
Both are correct; appendices is more formal, appendixes more casual.
Can “appendices” refer to anatomy?
Yes, but “appendixes” is also acceptable in informal medical writing.
Are there regional differences?
British English prefers appendices, while American English accepts both.
Which style guides favor which form?
APA and MLA favor appendices; Chicago accepts both depending on context.
How do I know which one to use in my writing?
Consider audience, context, and style guide. Use appendices for formal writing, appendixes for casual content.
Key Takeaways
- Appendix = singular; appendices or appendixes = plural.
- Use appendices in formal, academic, and technical contexts.
- Use appendixes in informal writing or general English.
- Always label appendices clearly in reports, books, or articles.
- Knowing your audience and style guide ensures correct usage.
