The plural of appendix is appendices or appendixes. Both forms are grammatically correct, and both can refer to documentary supplements or the anatomical organ. Appendices is the traditional Latin-derived form and remains common in formal writing, while appendixes is the regular English plural and is especially common in general and medical usage.
Key Facts at a Glance
- Appendices and appendixes are both correct plural forms of appendix.
- Appendices is pronounced approximately uh-PEN-di-seez.
- Appendixes is pronounced approximately uh-PEN-dik-seez.
- A report may contain two appendices or two appendixes, depending on the selected style.
- Appendixes is not grammatically limited to anatomical organs.
- Appendices is not grammatically limited to academic documents.
- A publication’s style guide can require one form for consistency, even when both forms are correct.
What Is the Correct Plural of Appendix?
The correct plurals are appendices and appendixes. Writers may use either form when referring to more than one appendix, but the choice often depends on tradition, subject area, regional usage, or a publisher’s style guide.
The form appendices comes from the Latin plural pattern associated with appendix. The form appendixes applies the ordinary English plural ending -es. English has retained both forms, much as it has retained pairs such as indexes and indices, although the two forms can develop different specialist associations.
The most useful rule is consistency. If a university, journal, employer, or medical publisher specifies appendices, use that form throughout the document. If no style instruction exists, appendices suits formal reports and books, while appendixes is a clear and fully correct choice in ordinary English.
Is Appendices or Appendixes More Formal?
Appendices often sounds more formal because it is traditional and frequent in academic and publishing contexts. That impression reflects convention rather than a grammatical difference. Appendixes is not informal by definition, and professional organizations may use it in technical or medical documents.
A writer should not change a correct sentence merely because it contains appendixes. The sentence “The report contains three appendixes” is grammatically sound.
What Does Appendix Mean?
The noun appendix has two main meanings: supplementary material attached to a document and a narrow anatomical structure connected to the large intestine. Context usually makes the intended meaning clear.
In a book, thesis, contract, or report, an appendix contains supporting material that would interrupt the main discussion if placed in the body. Examples include survey instruments, raw datasets, interview transcripts, legal clauses, maps, formulas, and technical procedures.
In anatomy, the appendix usually means the vermiform appendix, a small, narrow, blind-ended tube connected to the cecum. Medical terms such as appendicitis and appendectomy derive from this anatomical sense, but the plural remains a language question rather than a medical diagnosis.
What Is the Plural of Appendix in a Report?
A report can contain appendices or appendixes. For example, “Appendices A and B contain the questionnaire and statistical tables” is correct, while “Appendixes A and B contain the questionnaire and statistical tables” is also correct.
Many academic institutions prefer appendices, particularly in theses and dissertations. The preference may come from a local thesis handbook, APA-based instructions, or a department’s established template. Grammar alone does not require the traditional form.
If a report has one supplementary section, label it Appendix. If it has several, label them Appendix A, Appendix B, and so forth, or use a numbered system such as Appendix 1 and Appendix 2.
When Should You Use Appendices?
Use appendices when a formal style guide, publisher, institution, or established document tradition favors the Latin-derived plural. The form is especially familiar in academic theses, research reports, books, legal agreements, and edited publications.
Examples include:
- “The full interview transcript appears in Appendix A.”
- “The statistical calculations are provided in Appendices B and C.”
- “The contract includes several appendices containing technical specifications.”
- “The book’s appendices document the source material.”
The word appendices does not require the material to be scholarly. A business proposal, government form, engineering manual, or contract may use the same plural. The deciding factor is the document’s style, not the subject alone.
How Should Multiple Documentary Appendices Be Labeled?
Label multiple documentary appendices with a consistent sequence, such as Appendix A, Appendix B, and Appendix C. Place each label in the table of contents when the document’s length and formatting system support one.
A practical document system includes four elements:
- A descriptive title, such as Appendix A: Survey Questionnaire.
- A cross-reference in the main text, such as “See Appendix A.”
- Page numbers that follow the document’s pagination rules.
- Consistent table and figure labels, such as Table A1 and Figure B2.
Do not create an appendix merely to store unrelated notes. Supplementary material should support, document, or extend an argument made in the main text.
When Should You Use Appendixes?
Use appendixes when a publication’s style guide prefers the regular English plural, or when you want a straightforward plural that requires no Latin-based explanation. Appendixes is common in general English and appears in professional medical, technical, and reference writing.
Examples include:
- “The surgeon removed two inflamed appendixes during the study period.”
- “The manual contains appendixes with equipment specifications.”
- “The final chapter includes appendixes containing source documents.”
- “The encyclopedia lists several appendixes to the original edition.”
The form appendixes can describe documentary supplements as well as anatomical organs. Treating it as an anatomy-only plural is an oversimplification.
Is Appendixes Correct in Academic Writing?
Yes. Appendixes is correct in academic writing unless the relevant institution or publisher requires appendices. Academic convention may make appendices the safer default when no instructions are available, but convention does not make appendixes wrong.
A thesis author should check the institution’s formatting manual before choosing. Consistent labeling matters more than selecting one form based on a general assumption about formality.
Appendices vs. Appendixes: Which Form Should You Choose?
| Situation | Recommended default | Why | Example |
|---|---|---|---|
| University thesis | Appendices | Common institutional convention | “See Appendices A-C” |
| Research report | Appendices | Familiar in formal reporting | “The datasets appear in the appendices” |
| General business document | Appendixes or appendices | Both forms are standard | “The appendixes contain specifications” |
| Medical article | Journal preference | AMA and journal policies can differ | “The appendixes list patient criteria” |
| Anatomy textbook | Appendixes or appendices | Both can describe organs | “The appendixes were examined” |
| Legal contract | Contract template | Defined terms require consistency | “Appendices 1 and 2 form part of this agreement” |
| Quotation from a source | Original wording | Preserves textual accuracy | “[Appendixes]” if the source uses it |
The best choice is therefore conditional but not uncertain: both plurals are correct, and the publication’s instructions determine the preferred form. In an unregulated context, appendices is a conservative formal choice; appendixes is an equally grammatical regular plural.
Does Appendices Mean Something Different From Appendixes?
Usually, no. The two forms have the same basic dictionary meaning, although readers may associate appendices with documents and appendixes with anatomy or general English.
That association is a usage tendency, not a semantic rule. A document can contain appendixes, and a medical text can contain appendices. Meaning comes from context.
How Do You Pronounce Appendices and Appendixes?
Appendices is commonly pronounced uh-PEN-di-seez, with a final sound like “sees.” Appendixes is commonly pronounced uh-PEN-dik-seez, with the consonant sound from the singular retained before the plural ending.
| Form | Approximate pronunciation | Final sound | Common association |
|---|---|---|---|
| Appendix | uh-PEN-diks | “diks” | Singular document or organ |
| Appendices | uh-PEN-di-seez | “sees” | Traditional plural |
| Appendixes | uh-PEN-dik-seez | “k-seez” | Regular English plural |
| Appendix’s | uh-PEN-diks | Singular possessive | One appendix’s material |
| Appendices’ | uh-PEN-di-seez | Plural possessive | Several appendices’ titles |
| Appendixes’ | uh-PEN-dik-seez | Plural possessive | Several appendixes’ locations |
The pronunciation difference follows the spelling. Speakers should not pronounce appendices as though it were spelled appendixes, or pronounce appendixes without the consonant sequence represented by -xes.
How Do You Make Appendix Possessive?
The singular possessive is appendix’s, while the plural possessives are appendices’ and appendixes’. The apostrophe position shows whether one or more appendices own or relate to the following noun.
Examples:
- “The appendix’s title appears in the table of contents.”
One appendix has a title. - “The appendices’ page numbers continue from the main report.”
Several appendices have page numbers. - “The appendixes’ locations are listed in the index.”
Several appendixes have locations.
Do not write appendix’ for the singular possessive in standard modern English. The singular noun normally takes ’s, even though the word already ends in x.
How Does Appendix Compare With Similar Plurals?
| Singular | Plural 1 | Plural 2 | Typical distinction |
|---|---|---|---|
| Appendix | Appendices | Appendixes | Both meanings can overlap |
| Index | Indices | Indexes | Indices often mathematical or scientific |
| Formula | Formulae | Formulas | Formulae often formal or scientific |
| Syllabus | Syllabi | Syllabuses | Syllabuses is regular English |
| Memorandum | Memoranda | Memorandums | Both appear in professional writing |
| Bureau | Bureaux | Bureaus | Bureaus is common in English |
The comparison shows why no universal rule can assign one plural to one meaning. English frequently preserves an older plural while also accepting a regular English form.
A useful practitioner rule is to distinguish lexical correctness from editorial preference. A style guide may prefer appendices, but it does not necessarily classify appendixes as an error.
What Are Common Errors With Appendix Plurals?
| Error | Correct form | Explanation | Example |
|---|---|---|---|
| Appendixes is always wrong | Appendices or appendixes | Both are established plurals | “The report has two appendixes” |
| Appendices refers only to documents | Both meanings are possible | Context controls interpretation | “The appendices were removed” |
| Appendixes refers only to organs | Both meanings are possible | Regular plural also suits documents | “Technical appendixes are attached” |
| Appendixs | Appendices or appendixes | The spelling lacks the correct plural ending | “Appendices A and B” |
| Appendixes A and Appendix B | Appendixes A and B | Mixed forms are inconsistent | Use one system |
| Appendix’s for several items | Appendices’ or appendixes’ | Singular and plural possessives differ | “The appendices’ tables” |
The most common practical error is inconsistency. A report that begins with Appendix A and later refers to “the appendixes” is not grammatically impossible, but a consistent editorial system is easier for readers to follow.
Should You Correct Appendixes to Appendices?
Correct appendixes only when the target style guide requires appendices, the document uses a deliberate formal convention, or consistency with surrounding terminology matters. Do not make the change solely because appendixes looks less sophisticated.
Editors should also preserve the original form in a quotation unless the quotation is being silently modernized under an explicit editorial policy. A source’s choice of appendixes may be intentional, regional, or part of its house style.
Do British and American Writers Use Different Forms?
British and American writers use both appendices and appendixes, although frequency can vary by publication, field, and editorial tradition. Regional English does not impose a strict rule that assigns one plural to one meaning.
Academic and legal publishers in both varieties often favor appendices because of its traditional status. General English, technical writing, and some medical publications use appendixes more readily. A particular journal’s instructions are stronger evidence than a broad regional assumption.
The distinction is therefore probabilistic rather than absolute. Writers should avoid statements such as “Americans must write appendixes” or “British writers must write appendices.”
What Do Style Guides Say About Appendix?
Style guides generally treat the plural as a matter of accepted usage and consistency, while individual publishers may select one form. APA, MLA, Chicago, AMA, university manuals, and journal instructions can differ in terminology, capitalization, placement, and labeling.
A style guide may regulate more than the plural itself:
- Whether appendices appear before or after references.
- Whether each appendix receives a letter or number.
- Whether Appendix is capitalized in a cross-reference.
- How appendix tables and figures are numbered.
- Whether an appendix title appears in the table of contents.
- How online supplementary files are named.
Follow the governing guide for the document. If no guide applies, choose one plural and use it consistently.
Is Appendix Capitalized?
Capitalize Appendix when it is part of a specific title or numbered label, such as Appendix A or Appendix: Survey Questions. Use lowercase when referring to an appendix generically.
Examples:
- “The full questionnaire appears in Appendix A.”
- “The report includes three appendices.”
- “See the appendix for the calculation details.”
- “The material is provided in Appendix B.”
Capitalization follows the reference’s function, not the plural form. The same rule applies to Appendices A and B when the word begins a formal label.
Can You Use Both Plural Forms in One Document?
You can use both forms when they refer to different quoted sources, named works, or intentionally distinct editorial systems, but ordinary prose should normally use one form consistently. Mixing forms without a reason creates an avoidable impression of error.
For example, a scholarly editor might write: “The original edition called these sections ‘appendixes,’ while the revised edition labels them ‘appendices.’” The two spellings are justified because they reproduce separate source conventions.
A single report should normally choose appendices or appendixes, then retain that choice in headings, cross-references, captions, and the table of contents. Terminological consistency reduces copyediting problems and helps readers navigate long documents.
FAQ
What Is the Plural of Appendix in British English?
The plural is appendices or appendixes in British English. Appendices is common in formal and academic writing, but British English does not prohibit appendixes. Use the form required by the publisher or institution, and apply it consistently throughout the document.
Is Appendices the Only Correct Spelling?
No. Appendices is not the only correct spelling. Appendixes is also a standard plural of appendix. Writers sometimes believe the Latin-derived form is mandatory because it appears frequently in academic documents, but frequency and correctness are separate questions.
What Is the Plural of a Body Appendix?
The plural of an anatomical appendix is appendixes or appendices. Medical writers may prefer appendixes in some publications because it clearly follows the English plural pattern, but medical context does not make appendices incorrect.
Should I Write Appendices or Appendixes in a Resume?
Use the form that matches the resume’s context and the relevant employer’s style, although resumes rarely need the word. If referring to supporting sections in a formal portfolio, appendices is a conventional choice. If the document uses plain English throughout, appendixes is also grammatically valid.
Is Appendix a Latin Word?
Appendix entered English through Latin and ultimately relates to something attached or added. English retained the Latin-derived plural appendices while also creating the regular plural appendixes. The word’s history explains the two forms, but modern English usage accepts both.
What Is the Opposite of an Appendix in a Document?
A document appendix contains supporting material placed outside the main argument, so it has no exact grammatical opposite. The closest contrast is the main text, body, or 正文 of the document, where the primary explanation and evidence appear.
The Bottom Line
The answer to “whats the plural of appendix” is appendices or appendixes. Choose appendices for a traditional formal default, especially when a university or publisher expects it, and choose appendixes when a style guide or plain-English convention favors the regular English plural. Neither form is universally restricted to documents or anatomy.
