Ever heard someone say “they did it theirselves” and wondered if that sounded right? That small moment of confusion is very common, especially when speaking or writing quickly.
This question often comes up for students, writers, English learners, and content creators who want to use correct grammar but get confused by words that sound natural in conversation.
Both themselves and theirselves may seem logical, but only one follows standard English rules.
The problem is simple: one is correct, and the other is considered nonstandard or incorrect in formal writing. But many people still use the wrong form without realizing it.
In this guide, everything is explained clearly and simply.
By the end, you’ll know exactly which word to use, why it’s correct, and how to avoid this common mistake in everyday English.
Quick Answer
Meaning
- Themselves = correct reflexive pronoun
- Theirselves = nonstandard and incorrect in formal English
Examples
- They completed the task themselves. ✅
- They completed the task theirselves. ❌
Final Answer
Always use themselves in correct English.
The Origin of Themselves or Theirselves
History
Reflexive pronouns in English developed from combining pronouns with “self” or “selves.”
Development
- Themselves became the standard plural reflexive form
- Theirselves appeared in informal speech but never became standard
Why the Difference Exists
Language evolves through usage, but not all forms become grammatically accepted.
British English vs American English Spelling
Usage Comparison
| Version | Correct Form | Incorrect Form |
|---|---|---|
| British English | Themselves | Theirselves |
| American English | Themselves | Theirselves |
Key Insight
Both British and American English agree:
👉 Themselves is correct
👉 Theirselves is not standard
Which Spelling Should You Use?
Formal Writing
Always use themselves in essays, emails, and professional writing.
Informal Speech
You may hear theirselves in casual conversation, but avoid using it in writing.
Best Practice
Stick with themselves in all situations to stay safe.
Common Mistakes with Themselves or Theirselves
Using Theirselves in Writing
This is the most common mistake and should be avoided.
Thinking It Sounds Logical
Many people assume “theirselves” fits the pattern, but it does not follow standard grammar rules.
Mixing Formal and Informal English
Using nonstandard forms in formal contexts reduces clarity and professionalism.
Themselves or Theirselves Meaning (Detailed)
Themselves Meaning
- A reflexive pronoun
- Refers back to a plural subject
- Used to show that the subject performs an action on itself
Theirselves Meaning
- Nonstandard form
- Used in some dialects
- Not accepted in formal English
Themselves or Theirselves in Everyday Examples
Workplace
- Employees should manage themselves properly.
School
- Students prepared themselves for the exam.
Conversation
- They fixed the problem themselves.
Incorrect Example
- They fixed the problem theirselves. ❌
Themselves or Theirselves – Google Trends & Usage Data
Popularity
- Themselves is widely used and accepted
- Theirselves appears rarely and mostly in informal contexts
Insight
Search trends clearly show that themselves dominates in correct usage.
Comparison Table: Themselves vs Theirselves
| Feature | Themselves | Theirselves |
|---|---|---|
| Correctness | ✅ Correct | ❌ Incorrect |
| Usage | Formal & Informal | Informal only |
| Grammar | Standard | Nonstandard |
| Popularity | Very High | Low |
FAQs
What is the difference between themselves and theirselves?
Themselves is the correct reflexive pronoun, while theirselves is nonstandard and not used in formal English.
Is theirselves a real word?
It exists in informal speech but is not accepted in standard grammar.
Why is theirselves incorrect?
Because it does not follow standard English reflexive pronoun rules.
When should I use themselves?
Use it when referring to a plural subject performing an action on itself.
Can I use theirselves in casual conversation?
It may be used in informal speech, but it is best avoided.
Is themselves used in both UK and US English?
Yes, both use themselves as the correct form.
Conclusion
The confusion between themselves or theirselves is common, but the answer is simple once you understand the rules. Only one of these forms is correct in standard English.
Themselves is the proper reflexive pronoun used in both formal and informal contexts. It follows standard grammar rules and is accepted worldwide.
On the other hand, theirselves is considered nonstandard and should not be used in professional or academic writing.
While you might hear “theirselves” in casual speech, relying on it in writing can make your content appear incorrect or less polished. That’s why it’s always better to choose the correct and widely accepted form.
By sticking with themselves, you ensure clarity, correctness, and professionalism in your communication.
Now you can write confidently without second guessing this common grammar mistake.
Eric White is a dedicated grammar enthusiast and content writer at Grammiffy, where he simplifies the rules of English for learners of all levels. With a clear, reader-first approach, Eric focuses on grammar fundamentals, common mistakes, sentence structure, and everyday language usage.
