Many English learners and professional writers wonder if endeavour or endeavor is the correct spelling. The answer is simple. Both spellings are correct, but each belongs to a different variety of English.
Endeavour or Endeavor is a common spelling comparison that confuses many English learners and writers. Both words have the same meaning and refer to making a serious effort to achieve a goal. The only difference is the regional spelling. Endeavour is the preferred spelling in British English, while Endeavor is the standard spelling in American English. Knowing which version to use helps you write more accurately for your audience.
If you have ever wondered which spelling is correct, this guide will make it easy to understand. You will learn the meaning of both words, their differences, where each spelling is used, and practical examples to help you choose the right one with confidence.
Choose endeavour for readers in the United Kingdom and many Commonwealth countries. Choose endeavor for readers in the United States. Using the spelling that matches your audience creates consistency and professionalism.
Quick Answer
| British English | American English |
|---|---|
| Endeavour | Endeavor |
Both words mean a serious effort or attempt to achieve something. They can also be used as verbs meaning to try hard.
Examples
British English
- She will endeavour to complete the report today.
- The charity supports scientific endeavour.
American English
- She will endeavor to complete the report today.
- The project required a great deal of human endeavor.
Meaning of Endeavour and Endeavor
The meaning does not change between spellings.
As a noun, the word refers to a determined effort toward a goal.
Example
- Their research was a remarkable endeavor.
As a verb, it means to make a serious attempt.
Example
- We will endeavor to improve customer service.
British English vs American English
The spelling difference follows a common pattern between British and American English.
British English often keeps the our ending.
Examples include
| British | American |
|---|---|
| endeavour | endeavor |
| colour | color |
| favour | favor |
| honour | honor |
| labour | labor |
American English usually removes the letter u to simplify spelling.
Why Are There Two Spellings?
The variation comes from spelling reforms that became popular in the United States during the nineteenth century.
American dictionaries and publishers gradually adopted shorter spellings such as color, honor, and endeavor. British English continued using the traditional spellings, including endeavour.
Today, both forms are accepted within their respective language standards.
Dictionary Recommendations
Leading dictionaries recognize both spellings.
| Dictionary | Recommendation |
|---|---|
| Oxford English Dictionary | Lists both spellings based on regional English. |
| Cambridge Dictionary | Uses endeavour in British English and endeavor in American English. |
| Merriam Webster | Uses endeavor as the standard American spelling. |
| Collins Dictionary | Accepts both spellings and identifies their regional use. |
Official Style Guide Recommendations
Different style guides recommend the spelling that matches their regional standard.
| Style Guide | Preferred Spelling |
|---|---|
| Chicago Manual of Style | Endeavor |
| AP Style | Endeavor |
| Oxford Style Manual | Endeavour |
| New Hart’s Rules | Endeavour |
The most important rule is consistency throughout your document.
Publishing Standards
Publishers normally expect writers to follow one variety of English from beginning to end.
Choose endeavour for
- UK books
- British newspapers
- Commonwealth publications
Choose endeavor for
- US publishers
- American magazines
- US websites
Avoid mixing both spellings in the same article unless discussing language differences.
Academic Writing
Universities generally expect students to follow the regional English chosen for their institution.
For example
- British universities usually prefer endeavour.
- American universities usually require endeavor.
Always follow your instructor’s or publisher’s style requirements.
Business Writing
Businesses should use the spelling that matches their target market.
For UK customers
- We endeavour to provide outstanding service.
For US customers
- We endeavor to provide outstanding service.
International companies often create separate British and American versions of marketing materials.
International Communication
If your audience includes readers from multiple countries, consistency is more important than choosing one spelling over the other.
Many international organizations select either British or American English as their official writing standard and use it across all documents.
Real World Examples
British English
- Our team will endeavour to meet every deadline.
- Scientific endeavour continues to improve healthcare.
- The company endeavours to reduce waste each year.
American English
- Our team will endeavor to meet every deadline.
- Scientific endeavor continues to improve healthcare.
- The company endeavors to reduce waste each year.
History of the Spelling
The word comes from the Old French expression meaning to put into duty or effort. It entered Middle English centuries ago and developed into endeavour in British English.
During American spelling reforms, many words ending in our changed to or, producing endeavor. Both spellings have remained standard ever since.
Current Usage Trends
British publications overwhelmingly use endeavour.
American newspapers, businesses, universities, and government organizations almost always use endeavor.
Online searches show that each spelling remains dominant within its own region, making audience awareness the key factor when choosing between them.
Common Mistakes
Do not switch between endeavour and endeavor in the same document.
Use the spelling that matches your chosen style guide.
Do not assume one spelling is incorrect because it differs from your regional English.
Remember that both spellings have the same pronunciation and meaning.
Which Spelling Should You Choose?
Choose endeavour if you are writing for
- United Kingdom
- Australia
- New Zealand
- Ireland
- Many Commonwealth countries
Choose endeavor if you are writing for
- United States
- American businesses
- US academic institutions
- American publishers
Frequently Asked Questions
Is endeavour correct?
Yes. Endeavour is the standard British English spelling.
Is endeavor correct?
Yes. Endeavor is the standard American English spelling.
Do both words have the same meaning?
Yes. Both mean a serious effort or an attempt to achieve something.
Which spelling should I use for SEO?
Use the spelling your audience is most likely to search for. If your readers are mainly in the United Kingdom, use endeavour. For readers in the United States, use endeavor.
Can I use both spellings in one article?
Only when comparing British and American English. Otherwise, keep one spelling throughout your content.
Conclusion
Endeavour and endeavor are both correct spellings of the same word. The only difference is regional usage. British English uses endeavour, while American English uses endeavor. The meaning, pronunciation, and grammar remain the same. Choose the spelling that matches your audience, follow the appropriate style guide, and use it consistently throughout your writing for clear and professional communication.
Olivia Bennett is a grammar expert and language content writer at GrammarWize.com. She specializes in English grammar, word usage, spelling differences, and writing improvement. Through clear explanations and practical examples, Olivia helps students, professionals, and language learners communicate more effectively. Her goal is to make English grammar simple, accessible, and easy to apply in everyday writing.
