If you’ve ever paused while writing their life or their lives, you’re not alone. Both phrases are grammatically correct, but they serve different purposes. The choice depends on whether you’re talking about one life or multiple lives. Once you understand that simple rule, you’ll stop second-guessing yourself.
Whether you’re writing an email, a school paper, a blog post, or a novel, using the correct form makes your writing clearer and more professional. This guide explains every rule with practical examples, comparison tables, and common mistakes so you can use each phrase confidently.
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Quick Answer: Is It “Their Life” or “Their Lives”?
The answer depends on how many lives you’re referring to, not on the word their.
| Phrase | Use It When | Example |
| Their life | One person’s life | Every student deserves to live their life without fear. |
| Their lives | More than one person’s lives | The firefighters risked their lives to save the family. |
The Short Rule
Think about the noun after their.
- If you’re talking about one life, write their life.
- If you’re talking about more than one life, write their lives.
Many writers assume their always requires a plural noun. That’s incorrect. The pronoun their can refer to one person when English uses singular they.
Five Quick Examples
Correct:
- Every child deserves their life to be filled with opportunity.
- Someone forgot their life story notebook.
- The soldiers sacrificed their lives for their country.
- The survivors rebuilt their lives after the disaster.
- The doctors dedicated their lives to helping others.
What Does “Their Life” Mean?
Their life refers to the life of one person.
That person might not be identified by gender, or you may intentionally choose gender-neutral language.
Definition
Their life means:
The single life belonging to one individual.
This is common in modern English because singular they has become the preferred gender-neutral pronoun in many situations.
When It Is Grammatically Correct
Use their life when:
- the subject is singular
- the person’s gender isn’t known
- gender doesn’t matter
- you’re writing inclusively
Examples:
- Every employee should enjoy their life outside work.
- If anyone changes careers, their life may improve.
- A student should balance their life between study and rest.
Notice something interesting?
Although their looks plural, life stays singular because only one person owns one life.
Using Singular They
English speakers have used singular they for centuries.
Instead of writing:
Every student should enjoy his or her life.
Modern English prefers:
Every student should enjoy their life.
This sounds smoother and avoids awkward repetition.
Example Sentences
- Everyone deserves to live their life with dignity.
- No one should fear losing their life because of discrimination.
- Each athlete works hard to improve their life through sport.
- If a customer changes careers, their life might change completely.
What Does “Their Lives” Mean?
Unlike their life, their lives refers to multiple lives.
Usually, several people each have their own individual life.
Definition
Their lives means:
The lives belonging to two or more people.
When the Plural Form Is Required
Use their lives when:
- talking about several people
- describing a group’s experiences
- discussing individual lives collectively
Examples include:
- Parents influence their lives in different ways.
- Refugees rebuilt their lives after the conflict.
- Scientists devoted their lives to research.
Example Sentences
- The volunteers changed their lives forever.
- Many immigrants improved their lives through education.
- The rescue team risked their lives during the operation.
- Teachers shape their lives every day.
Why It Is the More Common Form
Because many conversations involve groups, their lives appears frequently in books, news articles, and everyday speech.
Examples:
- improve their lives
- save their lives
- change their lives
- rebuild their lives
- dedicate their lives
These expressions appear thousands of times across newspapers and published books.
Their Life vs. Their Lives: The Key Difference
The confusion becomes simple once you focus on the noun instead of the pronoun.
| Feature | Their Life | Their Lives |
| Number | Singular | Plural |
| Refers to | One person | Multiple people |
| Uses singular they | Yes | Sometimes |
| Common in inclusive writing | Yes | Less often |
| Example | Every person deserves their life. | They rebuilt their lives. |
Meaning Changes Based on Number
Consider these two sentences.
Every employee should enjoy their life.
Only one employee’s life is being discussed.
Now compare it with:
Employees should enjoy their lives.
Now we’re discussing many employees.
The only difference is the number of lives involved.
Visual Grammar Breakdown
One Person
│
▼
Their + Life
Many People
│
▼
Their + Lives
Whenever you’re unsure, ask yourself one question:
How many lives am I talking about?
The answer almost always tells you which form to use.
Why “Their Life” Can Still Be Singular
This is where many learners become confused.
They assume:
their = plural
Modern English doesn’t always work that way.
Understanding Singular They
Singular they refers to one individual.
Examples include:
- everyone
- anyone
- somebody
- no one
- each person
Example:
Everyone should enjoy their life.
Although everyone refers to many people collectively, grammatically it acts as a singular subject.
Referring to One Person Without Specifying Gender
Imagine writing:
Every applicant should submit his or her résumé.
That sounds formal and repetitive.
Instead:
Every applicant should submit their résumé.
The same idea applies with their life.
Modern Grammar and Style Guide Recommendations
Major publishers, universities, and professional organizations now recommend singular they because it is:
- natural
- inclusive
- concise
- widely understood
Instead of repeating he or she, writers now prefer they, their, and them when referring to one unidentified person.
That change affects phrases like their life, making them perfectly correct in modern English.
When “Their Lives” Is the Only Correct Choice
Sometimes there is no choice at all.
If multiple people each have a separate life, the plural noun is required.
Examples:
- The doctors saved their lives.
- Soldiers risked their lives.
- The families rebuilt their lives.
- Students transformed their lives through education.
Using their life here would sound incorrect because multiple lives are involved.
How Subject Number Determines the Correct Form
One of the easiest ways to avoid mistakes is to identify the subject before choosing the noun.
Singular Subjects
Words like these usually require their life:
- everyone
- each person
- anybody
- someone
- no one
- every customer
Examples:
- Everyone deserves their life to matter.
- Someone changed their life dramatically.
Plural Subjects
Plural nouns normally require their lives.
Examples:
- Children improve their lives through learning.
- Athletes dedicate their lives to training.
- Authors spend their lives writing books.
Indefinite Pronouns
Indefinite pronouns often confuse writers because they look plural but behave differently.
| Pronoun | Correct Phrase |
| Everyone | Their life |
| Someone | Their life |
| Anybody | Their life |
| Nobody | Their life |
| Several people | Their lives |
| Many workers | Their lives |
Compound Subjects
When two or more people share the subject, the plural noun almost always follows.
Examples:
- Sarah and Emma changed their lives.
- The brothers valued their lives.
- Teachers and parents shape their lives differently.
Understanding Singular They in Modern English
Singular they isn’t a new invention.
In fact, writers have used it for hundreds of years.
Authors from the Middle Ages through modern literature regularly used singular they when the person’s gender was unknown or irrelevant. Over time, English speakers continued the habit because it sounds natural in conversation.
Today, many respected style guides—including those used by universities, publishers, and major news organizations—recognize singular they as standard English. That means sentences like “Every student should make the most of their life” are widely accepted in both formal and informal writing.
Historically, some teachers insisted on using he as a generic pronoun. Later, writers often switched to he or she, which solved one problem but created another. Repeating that phrase throughout a document makes writing feel heavy and repetitive.
Singular they offers a cleaner solution.
Compare these examples:
- Every employee should enjoy his or her life outside work.
- Every employee should enjoy their life outside work.
The second sentence flows better while remaining clear and inclusive.
In everyday conversation, most native English speakers naturally choose their without stopping to think about the rule. That’s one reason why singular they continues to grow in popularity across business writing, journalism, education, and online communication.
FAQs
Is their life grammatically correct?
Yes. Their life is grammatically correct when you’re referring to one person’s life. This commonly happens with singular they, which English speakers use when a person’s gender is unknown, unspecified, or intentionally left neutral.
Example:
Every student should make the most of their life.
When should I use their lives instead of their life?
Use their lives whenever you’re talking about two or more people, with each person having their own life.
Examples:
- The firefighters risked their lives to save the family.
- The graduates changed their lives through education.
A simple rule is to ask yourself, “Am I referring to one life or several lives?”
Can their refer to one person?
Absolutely. In modern English, their, them, and they can refer to a single person. This usage is known as singular they, and it is accepted in academic, professional, and everyday writing.
Example:
If anyone calls, tell them I’ll return their message.
Why is singular they considered correct?
Singular they has existed in English for hundreds of years. Today, it is widely accepted because it is natural, inclusive, and avoids awkward phrases like he or she.
Many respected publishers, universities, and style guides recommend using singular they whenever it improves clarity and readability.
Is their life appropriate in formal writing?
Yes. Their life is appropriate in formal writing when it refers to one individual using singular they. It appears regularly in business documents, academic writing, government publications, and professional communication.
The important thing is to make sure the noun life matches the intended meaning.
How do I know whether to use life or lives?
Focus on the noun rather than the pronoun.
- Use life when discussing one person’s life.
- Use lives when discussing multiple people’s lives.
This simple check prevents most grammar mistakes.
Do American and British English follow the same rule?
Yes. Both American English and British English follow the same grammatical rule. The difference isn’t regional. It depends entirely on whether you’re referring to one life or multiple lives.
Why do writers often confuse their life and their lives?
The confusion happens because their traditionally functions as a plural possessive pronoun. Many writers mistakenly assume the following noun must also be plural.
However, that’s not how English grammar works. The noun changes based on how many lives are being discussed, not on the pronoun itself.
Is their lives ever incorrect?
Yes. Their lives becomes incorrect when you’re referring to only one person’s life.
For example:
❌ Every employee should improve their lives.
✅ Every employee should improve their life.
The corrected sentence refers to one employee at a time, so the singular noun is required.
What’s the easiest way to remember the difference between their life and their lives?
Remember this simple rule:
- One person = their life
- More than one person = their lives
Conclusion
Understanding the difference between their life and their lives becomes much easier once you focus on how many lives you’re describing. If you’re referring to one person’s life, even with singular they, their life is the correct choice. If you’re talking about multiple people, each with their own life, then their lives is the grammatically accurate form.
Although these phrases differ by just one letter, choosing the right one makes your writing clearer, more natural, and more professional. Whether you’re writing an academic paper, a business email, a blog post, or simply chatting online, using the correct form helps your message read smoothly and avoids unnecessary confusion.
Whenever you hesitate, remember this simple rule: one person means “their life,” while multiple people mean “their lives.” With that guideline in mind—and the examples, comparison tables, and practice exercises from this guide—you’ll be able to use both expressions confidently in any writing situation.
Hi, I’m Emily Harrington — the creator of Grammar Orbits. I simplify grammar so students and writers can communicate with clarity and confidence.
