Have you ever paused while writing and wondered whether the correct plural of appendix is appendixes or appendices? You are not alone.
This question confuses students, writers, researchers, editors, and professionals because both words appear in dictionaries and published writing.
The good news is that both plurals are correct, but they are used in different contexts. Understanding when to use each form will make your writing clearer and more professional.
In this guide, you’ll learn the meaning of appendix, the correct plural forms, their differences, real-world examples, and the grammar rules behind them.
By the end, you’ll know exactly which word to use in reports, research papers, books, and everyday writing.
Appendixes or Appendices – Quick Answer
Both appendixes and appendices are correct plural forms of appendix. The difference is not one of grammar but of style, context, and audience.
Appendixes is the regular English plural formed by adding -es. It is commonly used in general English, business documents, manuals, websites, blogs, and everyday writing.
Appendices is the traditional Latin plural. It is more common in academic writing, research papers, scientific journals, legal documents, technical reports, and formal publications.
If you are unsure which form to choose, remember this simple rule:
- Appendixes → Best for general or everyday writing.
- Appendices → Best for formal, academic, and professional writing.
Both words refer to the same thing. Choosing the right one depends on your audience rather than on correctness.
For example:
- The instruction manual includes three appendixes explaining the installation process.
- Please refer to Appendices A and B for the complete research data.
- The company’s annual report contains several financial appendices.
- The book ends with two useful appendixes for further reading.
Correct Examples
The following sentences use the correct plural based on their context.
General English
- The textbook includes two appendixes with extra exercises.
- Our training guide has several appendixes that explain technical terms.
- Please read the appendixes before installing the software.
- The handbook contains useful appendixes for new employees.
Academic and Professional Writing
- The complete survey results are available in Appendices A–D.
- Readers can find supporting evidence in the report’s appendices.
- The thesis contains five appendices with interview transcripts.
- Additional statistical data appear in the appendices at the end of the journal article.
These examples show that the meaning stays exactly the same. Only the writing style changes.
Incorrect Examples
Most mistakes happen because writers misunderstand how the two plural forms should be used or mix them within the same document.
Incorrect:
- The report includes several appendix. ❌
Correct:
- The report includes several appendices. ✅
Incorrect:
- The book has two appendix at the end. ❌
Correct:
- The book has two appendixes at the end. ✅
Incorrect:
- See Appendix A, B, and C for more information. ❌
Correct:
- See Appendices A–C for more information. ✅
Incorrect:
- This paper contains three appendixes, while the next page refers to the appendices. ❌
Correct:
- Choose one plural form and use it consistently throughout the document. ✅
A common misconception is that appendixes is wrong because appendices sounds more formal. In reality, both are accepted by major English dictionaries. The best choice depends on the purpose of your writing.
What Does Appendix Mean?
Before deciding between appendixes and appendices, it helps to understand what the singular word appendix actually means.
The word has more than one meaning in English, and the intended meaning often determines the context in which the plural appears.
In modern English, appendix is most commonly used in two ways:
- An additional section placed at the end of a book, report, thesis, or research paper.
- A small tube-shaped organ attached to the large intestine in the human body.
Although these meanings are completely different, they share the same singular form and the same accepted plural forms.
Common Meanings
1. Appendix as a Section in a Book or Report
In writing, an appendix is a section added after the main content to provide extra information without interrupting the flow of the document.
An appendix may include:
- Charts
- Tables
- Survey results
- Interview transcripts
- Maps
- Technical specifications
- Legal documents
- Reference material
- Images
- Supporting calculations
For example, a university research paper may place raw survey data in the appendix instead of the main chapters.
Likewise, a business report may include financial statements or product specifications in the appendices so readers can consult them when needed.
Examples:
- Please see Appendix A for the complete questionnaire.
- Additional graphs are included in the appendix.
- The report contains three appendices with supporting evidence.
- Readers can find detailed statistics in the appendices at the end of the document.
This is the meaning most people refer to when searching “appendix or appendices in report,” “what is appendices in report,” or “appendix or appendices in table of contents.”
2. Appendix as a Body Organ
The appendix is also a small, narrow organ attached to the large intestine. Although its exact purpose is still debated, modern research suggests it may play a role in supporting the immune system and maintaining beneficial gut bacteria.
People usually hear about the appendix in medical situations, especially when discussing appendicitis, an inflammation that often requires surgery.
Examples:
- The patient’s appendix became inflamed.
- Doctors removed her appendix during emergency surgery.
- The surgeon examined both appendices during the medical study.
- Medical textbooks describe the structure of the appendixes in different age groups.
In medical writing, appendices is generally more common because medical literature often follows traditional Latin plurals. However, appendixes is also considered correct in standard English.
Simple Usage Examples
Seeing the words in everyday sentences makes the difference much easier to remember.
Book
- The author added two appendixes containing historical documents.
- Refer to the appendices for additional reading materials.
Research Paper
- The complete dataset appears in Appendix B.
- Statistical analyses are presented in the appendices.
Business Report
- Sales figures are included in the appendices.
- The final report contains three appendixes explaining project costs.
Education
- Students should review the appendices before submitting the assignment.
- The textbook includes helpful appendixes with practice questions.
Medical Context
- The surgeon successfully removed the patient’s appendix.
- Researchers examined healthy appendices during the study.
No matter which meaning you intend, remember that appendix is singular, while appendixes and appendices are both accepted plural forms.
The next section explains why English has two different plurals for the same word and how this unique spelling developed over time.
The Origin of Appendixes or Appendices
Many English learners wonder why appendix has two accepted plural forms. Most English nouns follow one simple rule: add -s or -es to make them plural.
However, appendix is different because it comes from Latin, not Old English. As the word became part of English, both the original Latin plural and the regular English plural remained in use.
Today, dictionaries recognize appendixes and appendices as correct. The choice depends on writing style, audience, and context rather than grammar.
Understanding the history behind the word makes it easier to remember why both forms exist.
Word History
The word appendix comes from the Latin word appendix, which means “something attached” or “something added.” It comes from the Latin verb appendere, meaning “to hang upon” or “attach.”
Originally, the word referred to something added to the end of another document. Over time, English adopted the same word and later expanded its meaning to include the small organ attached to the large intestine.
When English borrowed Latin words, many kept their original Latin plural forms. For appendix, the Latin plural became appendices.
However, English also has its own pluralization rules. As English evolved, many writers naturally formed the plural by adding -es, creating appendixes.
Because both forms became widely accepted, modern dictionaries list both as correct.
This pattern appears in several other English words borrowed from Latin.
| Singular | English Plural | Latin Plural |
|---|---|---|
| Appendix | Appendixes | Appendices |
| Index | Indexes | Indices |
| Matrix | Matrixes | Matrices |
| Vertex | Vertexes | Vertices |
| Codex | Codexes | Codices |
Over time, some Latin plurals remained common in academic and scientific writing, while English plurals became more popular in everyday communication.
Why the Confusion Happens
People become confused because they often see appendices in research papers, textbooks, university assignments, and official reports. This makes many assume that appendixes is incorrect.
In reality, both are accepted by major English dictionaries and style guides.
The confusion usually comes from three reasons:
1. Latin vs English Grammar
Many people do not realize English borrowed thousands of words from Latin. Some of these words kept their original plurals, while others adopted regular English endings.
2. Different Writing Styles
Academic institutions often prefer traditional Latin plurals because they sound more formal.
General English prefers simple English plurals because they feel more natural to everyday readers.
3. Dictionary Preferences
Some dictionaries list appendices first because it is traditionally associated with formal writing. Others list both forms equally without giving preference.
The important point is that neither word is wrong.
Appendixes vs Appendices: What’s the Difference?
Although appendixes and appendices have exactly the same meaning, they are not always used in the same situations. The difference lies in style, tone, and audience rather than grammar.
If you understand where each form is commonly used, choosing the correct plural becomes very easy.
Appendixes vs Appendices Comparison Table
| Feature | Appendixes | Appendices |
|---|---|---|
| Correct spelling | ✅ Yes | ✅ Yes |
| Meaning | Plural of appendix | Plural of appendix |
| Origin | English plural | Latin plural |
| Tone | Neutral and everyday | Formal and academic |
| Common in | Blogs, manuals, websites, business writing | Research papers, journals, reports, theses |
| Easy for general readers | ✅ Yes | ✅ Yes |
| Preferred in higher education | Sometimes | ✅ Usually |
| Accepted by dictionaries | ✅ Yes | ✅ Yes |
The table shows that there is no difference in meaning. Both words refer to more than one appendix.
The only real difference is the writing style.
If your audience consists of everyday readers, customers, employees, or website visitors, appendixes sounds perfectly natural.
If you are writing for professors, researchers, scientists, or academic publishers, appendices is generally the better choice.
When Both Forms Are Acceptable
There are many situations where either plural sounds completely natural.
Examples:
- The user manual includes several appendixes explaining the software features.
- The user manual includes several appendices explaining the software features.
Both sentences are grammatically correct.
Likewise:
- The book contains two helpful appendixes.
- The book contains two helpful appendices.
Again, both versions are correct.
The important thing is to choose one spelling and use it consistently throughout your document.
Why Academic Writing Prefers Appendices
Universities, journals, and research institutions often use appendices because many academic style guides preserve traditional Latin plurals.
For example, a research paper may contain:
- Appendix A
- Appendix B
- Appendix C
Collectively, these become:
- Appendices A–C
Similarly, theses, dissertations, scientific studies, and government reports commonly use appendices because the term has become the standard in scholarly publishing.
This preference does not mean appendixes is incorrect.
It simply reflects the formal writing conventions used in higher education.
When Should You Use Appendixes?
Although appendices often appears in academic writing, appendixes is an equally correct plural and is widely used in general English.
Many modern writers prefer appendixes because it follows the regular English rule for forming plurals. It is easier to recognize, especially for readers who are unfamiliar with Latin-derived words.
General Writing
For blogs, magazines, articles, newsletters, and everyday documents, appendixes is a clear and natural choice.
Examples:
- The guide includes three appendixes with troubleshooting tips.
- Our handbook contains useful appendixes for new employees.
- Readers can find additional resources in the appendixes.
General audiences usually find this spelling more familiar because it follows normal English grammar patterns.
Blogs and Websites
Online writing should be simple and easy to understand.
If you are creating content for websites, tutorials, online courses, or help centers, appendixes often feels more approachable.
Examples:
- The article includes two appendixes with downloadable templates.
- Check the appendixes for printable worksheets.
- Extra examples appear in the appendixes below.
This spelling improves readability without changing the meaning.
Instruction Manuals
Many companies write technical documentation for customers rather than academics.
Examples include:
- Product manuals
- Software documentation
- Employee handbooks
- User guides
- Installation instructions
In these cases, appendixes fits naturally.
Example:
The installation guide includes four appendixes covering safety procedures and troubleshooting.
Everyday Communication
Emails, internal office documents, presentations, training materials, and general business communication often benefit from plain English.
Examples:
- I’ve attached two appendixes with additional information.
- Please review the appendixes before tomorrow’s meeting.
- The project file includes updated appendixes for each department.
Using appendixes makes the writing straightforward and accessible for most readers.
The next section explains why appendices remains the preferred choice for research papers, reports, theses, and other formal documents, and how to use it correctly in academic and professional writing.
When Should You Use Appendices?
Although appendixes is perfectly correct, appendices remains the preferred plural in many formal and academic settings.
Because it preserves the original Latin plural, it has long been associated with scholarly, scientific, legal, and professional writing.
If your document follows an academic style guide or is intended for researchers, professors, editors, or professional reviewers, appendices is usually the better choice.
Reports
Business reports, annual reports, government publications, and technical documents often place supporting material at the end of the document.
Instead of interrupting the main discussion, writers include detailed information in one or more appendices.
Common items found in appendices include:
- Financial statements
- Survey responses
- Technical specifications
- Product diagrams
- Legal documents
- Supporting calculations
- Maps and charts
Examples:
- The annual report includes three appendices containing financial data.
- Please refer to Appendices A–D for supporting documents.
- Additional project information appears in the appendices.
Using appendices in reports helps maintain a professional and consistent style, especially when the document may be shared with clients, government agencies, or stakeholders.
Research Papers
Research papers frequently contain information that supports the study but is too detailed for the main body of the paper.
Instead of placing lengthy tables or interview transcripts within the discussion, researchers include them in the appendices.
Typical research appendices include:
- Raw data
- Questionnaires
- Consent forms
- Interview transcripts
- Survey results
- Statistical analyses
- Experimental procedures
Examples:
- The complete questionnaire appears in Appendix A.
- Interview transcripts are included in the appendices.
- Readers can review the supporting data in the appendices.
Most universities and academic journals recommend using appendices because it aligns with established scholarly writing conventions.
Academic Writing
Students often ask whether they should write appendixes or appendices in assignments.
For most colleges and universities, appendices is the preferred option.
It commonly appears in:
- Essays
- Research projects
- Dissertations
- Laboratory reports
- Case studies
- Literature reviews
For example:
- See Appendix B for the complete survey.
- The appendices include additional reference materials.
- All supporting documents are listed in the appendices.
If your instructor provides a style guide, always follow those instructions. Otherwise, appendices is generally the safest choice for academic work.
Thesis and Dissertation
A thesis or dissertation often contains hundreds of pages. Supporting documents are usually placed after the references in separate appendices.
Common thesis appendices include:
- Ethics approval letters
- Research instruments
- Interview questions
- Participant information
- Coding frameworks
- Additional charts
- Statistical outputs
Example:
The complete interview transcripts can be found in Appendix C, while demographic tables appear in Appendix D.
When referring to all of them together, write:
The supporting materials are available in the appendices.
Using consistent labels such as Appendix A, Appendix B, and Appendices A–D makes large academic documents easier to navigate.
Appendix or Appendices in Reports
One of the most searched questions is whether a report should use appendix or appendices. The answer depends entirely on how many supplementary sections the report contains.
If there is one additional section, use appendix.
If there are two or more, use appendices (or appendixes in less formal writing, though appendices is preferred in reports).
Appendix or Appendices in a Report
Here is the simplest rule:
| Number of Sections | Correct Term |
|---|---|
| One | Appendix |
| Two or More | Appendices |
Examples:
- See Appendix A for the complete budget.
- Refer to Appendix B for technical specifications.
- Supporting information is available in Appendices A–C.
- Financial statements are included in the appendices.
Professional reports usually use letters to organize appendices:
- Appendix A
- Appendix B
- Appendix C
Collectively:
- Appendices A–C
This format is widely accepted in business, education, and government documents.
What Is Appendices in a Report?
In a report, appendices are sections placed after the main content to provide supporting information that would interrupt the flow if included in the body.
They allow readers to explore additional details without making the report difficult to read.
Appendices may contain:
- Tables
- Graphs
- Images
- Survey responses
- Contracts
- Technical drawings
- Data sets
- Questionnaires
- Calculations
- Reference documents
For example, a marketing report might summarize survey findings in the main text while placing the complete questionnaire and raw responses in the appendices.
This approach keeps the report organized and reader-friendly.
Appendix or Appendices in the Table of Contents
Another common question is how appendices should appear in a table of contents.
If your document has one appendix:
Appendix ……………………………. 45
If it has multiple appendices:
Appendix A – Survey Questions ………. 45
Appendix B – Interview Data …………. 52
Appendix C – Financial Statements ……. 61
Some style guides also allow:
Appendices …………………………. 45
followed by individual appendix titles underneath.
Whatever format you choose, keep it consistent throughout the document.
Appendixes or Appendices Examples
Seeing both plural forms in context makes the difference much easier to remember.
General Writing Examples
These examples use appendixes, which works well in everyday English.
- The handbook contains two appendixes with safety instructions.
- The guide includes several appendixes explaining technical terms.
- Check the appendixes for printable worksheets.
- Our employee manual has updated appendixes for each department.
- The software guide contains appendixes with troubleshooting tips.
These sentences sound natural because they are written for general readers.
Academic Examples
Academic writing generally favors appendices.
Examples:
- Refer to Appendices A and B for the survey results.
- The thesis includes four appendices containing interview transcripts.
- Additional statistical tables appear in the appendices.
- Supporting documents are located in the appendices after the references.
- Readers should consult the appendices before interpreting the results.
These examples reflect the style commonly found in universities and scholarly publications.
Business Examples
Business communication may use either plural depending on the company’s style guide, although formal reports often prefer appendices.
Examples:
- Please review the appendices before tomorrow’s board meeting.
- Financial forecasts are included in the appendices.
- The proposal contains appendices with product specifications.
- The audit report includes three appendices supporting the findings.
Maintaining one style throughout the document is more important than choosing one plural over the other.
Book Examples
Books often include appendices to provide readers with useful reference material.
Examples:
- The history book includes two appendixes containing historical maps.
- The cookbook features appendixes with measurement conversions.
- The novel ends with appendices explaining important historical events.
- Readers can explore additional resources in the appendices.
Whether you choose appendixes or appendices, the meaning remains exactly the same. The difference lies only in writing style and audience expectations.
Common Mistakes with Appendixes or Appendices
Both appendixes and appendices are correct, but writers often make mistakes because they are unsure which plural to choose. Most errors are caused by inconsistency rather than incorrect grammar.
The good news is that these mistakes are easy to avoid once you understand when each form is appropriate.
Frequent Errors
Here are some of the most common mistakes.
| Incorrect | Correct |
|---|---|
| The report contains three appendix. | The report contains three appendices. |
| The manual has two appendix. | The manual has two appendixes. |
| See Appendix A, B and C. | See Appendices A–C. |
| Mixing appendixes and appendices in the same report. | Choose one style and use it consistently. |
| Thinking appendixes is incorrect. | Both plurals are correct. |
| Using appendix for multiple sections. | Use appendixes or appendices. |
The biggest mistake is switching between both plural forms in the same document. While both are correct, consistency makes your writing look more polished and professional.
Corrected Examples
Below are examples showing the correct way to use each plural.
Incorrect
- The report contains three appendix.
- See Appendix A, B, and C.
- The appendixes contain survey data. Later, the appendices include interview notes.
Correct
- The report contains three appendices.
- See Appendices A–C.
- The appendices contain survey data and interview notes.
Or, if you choose the English plural:
- The report contains three appendixes.
- The appendixes include supporting documents.
Remember this simple rule:
- One = Appendix
- More than one = Appendixes or Appendices
Related Grammar Rules
Understanding appendixes and appendices becomes easier when you recognize that English contains many nouns borrowed from Latin.
Some writers prefer the English plural, while others keep the traditional Latin form.
Similar Spelling Mistakes
Here are several words that follow the same pattern.
| Singular | English Plural | Latin Plural |
|---|---|---|
| Appendix | Appendixes | Appendices |
| Index | Indexes | Indices |
| Matrix | Matrixes | Matrices |
| Vertex | Vertexes | Vertices |
| Codex | Codexes | Codices |
| Formula | Formulas | Formulae |
| Cactus | Cactuses | Cacti |
| Fungus | Funguses | Fungi |
Some Latin plurals are more common in academic writing, while English plurals are often preferred in everyday communication.
Helpful Grammar Tips
Use these simple grammar tips whenever you write.
- Appendix is singular.
- Appendixes and appendices are both correct plurals.
- Use appendices for research papers, reports, and academic writing.
- Use appendixes for blogs, manuals, and general English.
- If your organization follows a style guide, follow that preference.
- Never mix both plural forms within the same document.
- Label multiple sections as Appendix A, Appendix B, Appendix C, and refer to them collectively as Appendices A–C in formal writing.
- Proofread your document before publishing to ensure consistent usage.
Following these grammar rules will help your writing remain accurate, consistent, and professional.
FAQs
1. Which is correct, appendices or appendixes?
Both are correct. Appendixes is the regular English plural, while appendices is the traditional Latin plural commonly used in formal and academic writing.
2. What is the plural of an appendix?
The plural of appendix can be either appendixes or appendices, depending on the writing style and audience.
3. What is the difference between appendix and appendices?
Appendix is singular and refers to one section or one body organ. Appendices is a plural form used when referring to more than one.
4. Do you call it an appendix or appendices?
Use appendix when there is only one. Use appendices when there are two or more, especially in formal writing.
5. Why are there two plural forms of appendix?
Because appendix comes from Latin. English accepts both the traditional Latin plural (appendices) and the regular English plural (appendixes).
6. What is the meaning of the word appendixes?
Appendixes means more than one appendix, usually referring to additional sections at the end of books, reports, or manuals.
7. When should I use appendices vs. appendixes?
Use appendices in academic and professional documents. Use appendixes in general writing, blogs, manuals, and everyday communication.
8. Do you have two appendixes?
Yes. If you choose the English plural, you can correctly say two appendixes. In formal writing, many people would instead write two appendices.
9. What are the different ways to pluralize appendix?
There are two accepted plural forms: appendixes and appendices.
10. Do I title it Appendix or Appendices?
If there is one section, title it Appendix. If there are multiple sections, use Appendices or label them individually as Appendix A, Appendix B, and so on.
11. Are appendices useful?
Yes. Appendices provide supporting information such as tables, charts, questionnaires, and additional documents without interrupting the main text.
12. What is an example of an appendix?
An appendix might include a survey questionnaire, interview transcript, financial statement, or detailed chart placed after the main document.
13. What is an example of appendices?
A research paper may contain Appendix A (Survey Questions), Appendix B (Interview Data), and Appendix C (Statistical Tables). Together, these are called appendices.
14. Do sources or appendices go first?
In most academic style guides, the References or Works Cited section comes before the Appendices. Always check your required citation style.
15. Is appendices the plural of appendix?
Yes. Appendices is one of the two accepted plural forms of appendix.
16. Should the word “Appendix” be capitalized in a sentence?
Capitalize Appendix when it is followed by a letter or number, such as Appendix A. Use lowercase when referring to it generally.
17. What is an appendix in a report?
An appendix in a report is a section containing supporting information, such as tables, figures, calculations, or documents, that complements the main content.
18. What is appendices in a report?
Appendices are multiple supplementary sections placed at the end of a report to provide additional information without disrupting the main discussion.
19. What is the plural of appendix in academic writing?
Academic writing usually prefers appendices, although appendixes is also grammatically correct.
20. Is appendixes grammatically correct?
Yes. Appendixes is a standard English plural and is accepted by major dictionaries.
21. Is appendices grammatically correct?
Yes. Appendices is also grammatically correct and is especially common in scholarly and professional writing.
22. Which plural is preferred in formal writing?
Appendices is generally preferred in research papers, theses, academic journals, and formal reports.
23. Can I use appendixes and appendices in the same document?
No. Choose one plural form and use it consistently throughout your document.
24. Which plural is more common in modern English?
Both are widely accepted, but appendices appears more frequently in academic and formal publications, while appendixes is common in general English.
25. Which plural should I use?
If you are writing for a general audience, appendixes is a natural choice. For academic or professional writing, appendices is usually the preferred form.
Conclusion
Choosing between appendixes and appendices is much simpler once you understand the difference. Both plural forms are correct and accepted in modern English dictionaries.
Appendixes follows standard English plural rules and works well in blogs, manuals, and everyday writing. Appendices comes from the original Latin plural and is generally preferred in research papers, reports, theses, and other formal documents.
The most important rule is to remain consistent throughout your writing. Avoid switching between the two forms in the same document unless a specific style guide requires it.
By matching your choice to your audience and writing purpose, you can communicate more clearly, maintain a professional tone, and use the correct plural of appendix with confidence.
