Ever stared at the end of a report or research paper and wondered whether to label the extra section “appendices” or “appendixes”? 🤔
You’re not alone — both forms look right, and you’ve probably seen each used in books, journals, and academic documents. But here’s the twist: both are technically correct, yet they’re used in different contexts.
Although “appendices” sounds a bit more formal or academic, “appendixes” is equally accepted in modern English — it all depends on what you’re writing about and your preferred style guide.
In this article, we’ll break down what each form means, where to use it, and how to remember the difference with clear examples, a quick comparison chart, and practical writing tips.
What Is an “Appendix”?
✅ “Appendix” is a singular noun that refers to additional information added at the end of a book, document, or body part.
The word can mean two very different things, depending on context:
- In writing, it’s an extra section with supporting material.
- In anatomy, it’s a small tube-shaped organ attached to the large intestine.
1. Definition (in Writing)
Appendix = A supplementary section at the end of a book, report, or paper containing extra information, tables, or references.
Examples:
- “See Appendix A for detailed survey data.”
- “The research paper includes three appendices.”
- “All charts are listed in the appendix.”
🎯 Meaning: It helps readers access detailed or supporting data without cluttering the main content.
2. Definition (in Anatomy)
Appendix = A small, finger-like pouch located at the junction of the small and large intestines.
Examples:
- “She had her appendix removed last year.”
- “A ruptured appendix can cause severe pain.”
🎯 Meaning: A part of the digestive system — and the reason for many emergency surgeries!
What Are “Appendices”?
✅ “Appendices” is the traditional plural form of appendix — most commonly used in academic, literary, and formal writing.
1. Simple Definition
Appendices = Multiple supplementary sections or documents added to the end of a written work.
Examples:
- “The thesis includes two appendices for raw data and transcripts.”
- “All financial statements are provided in the appendices.”
- “Please refer to the appendices for a full list of sources.”
🎯 Usage Tip:
If you’re writing a book, report, research paper, or thesis, use appendices — it’s the preferred plural form in academic English.
2. Style Guide Preference
| Style Guide | Preferred Form | Example |
|---|---|---|
| APA (American Psychological Association) | Appendices | “See Appendices A and B.” |
| MLA (Modern Language Association) | Appendices | “Appendices contain supporting data.” |
| Chicago Manual of Style | Appendices | “Listed in Appendices A–C.” |
💡 Tip:
If your writing is academic, technical, or formal, stick with appendices — it’s considered more scholarly.
What Are “Appendixes”?
✅ “Appendixes” is also a correct plural of appendix, especially in everyday English or scientific/anatomical contexts.
1. Simple Definition
Appendixes = Multiple instances of the appendix (in a body) or multiple appendices (in writing) — modern alternative spelling.
Examples (Anatomy):
- “Doctors studied the removed appendixes.”
- “Both patients had inflamed appendixes.”
Examples (Writing):
- “Two appendixes were added to the manual.”
- “The report includes several appendixes.”
🎯 Usage Tip:
Use appendixes if your tone is modern, informal, or if your context is medical/scientific.
2. Style Guide Preference
| Field / Context | Preferred Form | Example |
|---|---|---|
| Medical Writing | Appendixes | “Multiple appendixes were examined.” |
| Everyday / Modern English | Appendixes | “See appendixes for more info.” |
| Academic / Formal | Appendices | “Refer to appendices at the end.” |
💡 Tip:
Both plural forms are correct — but appendices sounds more formal, while appendixes feels simpler and modern.
Key Differences Between “Appendices” and “Appendixes”
| Feature | Appendices | Appendixes |
|---|---|---|
| Plural of | Appendix | Appendix |
| Usage Context | Academic, literary, formal | Informal, scientific, modern |
| Preferred In | Research papers, books, reports | Medical texts, general writing |
| Tone | Scholarly / classic | Contemporary / casual |
| Example (writing) | “The report includes three appendices.” | “The manual includes several appendixes.” |
| Example (medical) | “—” | “Doctors studied inflamed appendixes.” |
🎯 Quick Rule:
Appendices = for documents and academic writing
Appendixes = for biology or everyday English
Real-Life Conversation Examples
Dialogue 1: Academic Setting
Student: “Should I label it ‘Appendixes’ or ‘Appendices’ in my thesis?”
Professor: “Use appendices — that’s standard in academic writing.”
🎯 Lesson: Academic = appendices.
Dialogue 2: Medical Discussion
Doctor A: “Both patients had infected appendixes.”
Doctor B: “Yes, that’s rare but possible.”
🎯 Lesson: In anatomy, appendixes fits better.
Dialogue 3: Everyday Use
Editor: “Do we use ‘appendices’ or ‘appendixes’ in this report?”
Writer: “Either works, but ‘appendices’ sounds more formal.”
🎯 Lesson: Both are correct — choose based on tone and audience.
When to Use “Appendices” vs “Appendixes”
| When to Use | Correct Form | Example |
|---|---|---|
| Writing a thesis or research paper | Appendices | “The appendices contain detailed results.” |
| Publishing a novel or report | Appendices | “See Appendices A–C for references.” |
| Discussing human anatomy | Appendixes | “Inflamed appendixes were removed.” |
| Speaking casually or modernly | Appendixes | “All appendixes are at the back of the file.” |
🎯 Simple Rule:
Academic = Appendices
Everyday / Medical = Appendixes
Fun Fact or History Section
📜 Did You Know?
- The word appendix comes from the Latin “appendere,” meaning “to hang upon” — fitting, since an appendix (in both books and bodies) is something that “hangs” off the main part.
- Historically, English preferred Latin-style plurals like appendices, but modern usage trends favor simpler English forms like appendixes.
- The same rule applies to other words:
- Index → indexes / indices
- Matrix → matrices / matrixes
So, both forms are fine — it’s all about your tone and audience.
Common Mistakes to Avoid
| ❌ Incorrect | ✅ Correct | Why |
|---|---|---|
| “My report includes two appendix.” | “My report includes two appendices.” | “Appendix” needs a plural form. |
| “Both appendixes are in Appendix A.” | “Both appendices are in Appendix A.” | In academic writing, use “appendices.” |
| “He had two appendix removed.” | “He had two appendixes removed.” | In anatomy, plural = “appendixes.” |
How to Remember the Difference
🧠 1. Think “Academic = Latin”
Formal, Latin-based writing prefers appendices.
🧠 2. Think “Anatomy = English”
Scientific and everyday English prefers appendixes.
🧠 3. Quick Mnemonic:
“Smart writers use appendices; smart doctors study appendixes.” 👨🏫👩⚕️
Mini Practice Quiz
Choose the correct plural 👇
- “The thesis includes three ___.” → Appendices ✅
- “The surgeons removed two ___.” → Appendixes ✅
- “Charts and figures are listed in the ___.” → Appendices ✅
- “The researcher added several ___ to support her findings.” → Appendices ✅
🎯 Answers: Appendices, Appendixes, Appendices, Appendices
Conclusion
To sum it up, both “appendices” and “appendixes” are correct, but their usage depends on context.
Use appendices for academic, technical, or formal documents, and appendixes for anatomical or casual writing. Both mean the plural of appendix, so you can’t go wrong as long as you match the tone to your field.
