If you are confused about someone or some one, you are not the only English learner who has wondered which spelling is correct. These two forms look almost identical, but they do not normally serve the same purpose in a sentence.
The standard form is someone when you mean an unspecified person. For example, “Someone is waiting outside” means that an unidentified person is waiting outside. In this meaning, someone is written as one word.
The two-word form some one is much less common. It can appear when some and one have separate grammatical roles, but many sentences that seem to require some one can be rewritten more naturally.
This guide explains someone or some one in detail, including meaning, grammar, spelling, sentence examples, common mistakes, related words, and frequently asked questions.
Someone or Some One: The Quick Answer
The easiest rule is:
Use “someone” when you mean “some person.”
For example:
- Someone called me yesterday.
- Someone is standing at the door.
- I need someone to help me.
- Someone left their phone here.
- Did someone ask for me?
In these sentences, someone is an indefinite pronoun referring to an unspecified person.
The two-word form some one has a more limited use. It can occur when some modifies one separately, especially when the writer wants to emphasize one particular person from a group.
For most everyday writing, however, someone is the form you need.
What Does Someone Mean?
Someone is an indefinite pronoun that means an unspecified person.
The word does not identify exactly who the person is. The identity may be unknown, unimportant, or deliberately left unstated.
For example:
Someone knocked on the door.
This sentence tells us that a person knocked on the door, but it does not tell us who that person was.
More examples include:
- Someone wants to speak with you.
- Someone took my notebook.
- Someone is waiting outside.
- Someone left a message.
- Someone knows the answer.
- I need someone to help me.
In every example, someone refers to a person whose identity is not specified.
Someone Means “Some Person”
A useful way to understand someone is to replace it mentally with some person.
For example:
Someone called you.
can be understood as:
Some person called you.
Another example:
Someone is using my computer.
means:
Some person is using my computer.
Because someone already carries this meaning, it is normally written as one word.
Why Is Someone Written as One Word?
English contains many indefinite pronouns that are written as single words.
Some common examples are:
- someone
- somebody
- something
- somewhere
- anyone
- anybody
- anything
- anywhere
- everyone
- everybody
- everything
- everywhere
These words developed into established forms with their own grammatical functions.
Someone is therefore normally treated as one complete word when it refers to an unspecified person.
For example:
Someone is calling you.
Here, someone functions as one pronoun.
Writing:
Some one is calling you.
would normally be considered incorrect if your intended meaning is simply an unspecified person.
When Should You Use Someone?
You should use someone when referring to an unknown, unspecified, or unnamed person.
Someone in Affirmative Sentences
Someone is frequently used in positive statements.
Examples:
Someone left the door open.
Someone wants to talk to you.
Someone knows what happened.
Someone took my pen.
Someone is waiting in the lobby.
The identity of the person is not given.
Someone in Questions
Someone can also appear in questions.
Examples:
Did someone call me?
Is someone waiting outside?
Can someone help me?
Has someone seen my keys?
Does someone know the answer?
The exact meaning can depend on context. In many questions, the speaker suspects that a particular but unidentified person may be involved.
Someone in Requests
Someone is especially common in requests for assistance.
Examples:
Can someone help me with this?
Could someone explain this question?
Will someone please answer the phone?
Can someone check the information?
In these examples, the speaker does not identify a particular helper.
Someone or Some One in Grammar
The main grammatical difference comes from how the words function.
Someone acts as a single indefinite pronoun.
For example:
Someone is outside.
The word someone is the subject of the sentence.
By contrast, some one can appear when some modifies one separately.
Consider a sentence such as:
Some one person in the group will have to make the decision.
Here, some describes one person. However, this construction is relatively uncommon in ordinary modern English. A more natural sentence would often be:
One person in the group will have to make the decision.
This is why learners should not automatically use some one simply because they see the words some plus one.
Is Some One Correct?
Some one is not completely impossible, but it is not the normal spelling when you mean someone.
If you want to say that an unspecified person did something, use someone.
Correct:
Someone opened the window.
Not normally correct for the intended meaning:
Some one opened the window.
The first sentence clearly means that an unidentified person opened the window.
In special constructions where some modifies one separately, the two-word form can occur. However, these situations are uncommon enough that most writers should use someone whenever they mean some person.
Someone or Some One: Sentence Examples
Looking at examples is one of the easiest ways to understand the difference.
Examples with Someone
Someone called while you were away.
Someone is sitting in my chair.
I need someone to explain this lesson.
Someone left their bag on the bus.
Someone knows where the keys are.
Someone has taken my book.
Did someone send this email?
Someone will contact you soon.
All these examples use someone as an indefinite pronoun.
Examples Where Some and One Are Separate
A sentence can sometimes use some before one when the writer is treating them as separate words.
For example:
Some one person must take responsibility.
However, this sentence sounds more natural as:
One person must take responsibility.
Another possibility is:
Some one of the students may know the answer.
In modern standard English, a clearer version would usually be:
One of the students may know the answer.
This demonstrates an important practical point: even when some one can be grammatically defensible in a particular construction, another wording may be more natural.
Someone Grammar Rules
Someone Takes a Singular Verb
Someone is grammatically singular.
Therefore, it normally takes a singular verb.
Correct:
Someone is waiting outside.
Incorrect:
Someone are waiting outside.
Correct:
Someone has called you.
Incorrect:
Someone have called you.
Correct:
Someone knows the answer.
Incorrect:
Someone know the answer.
Although someone refers to an unspecified person, it is grammatically treated as singular.
Someone With Their
Modern English commonly uses their after someone when the person’s gender is unknown or irrelevant.
For example:
Someone left their phone on the table.
Someone forgot their umbrella.
Someone should bring their identification.
This does not make someone plural. The indefinite pronoun remains grammatically singular, while their provides a gender-neutral reference.
Someone or Somebody
Someone is closely related to somebody.
Both words mean an unspecified person.
For example:
Someone called me.
Somebody called me.
Both sentences are grammatically correct.
The choice is often based on style, tone, or personal preference. Someone is a neutral choice that works well in everyday, professional, academic, and formal writing.
Someone or Anyone
Someone and anyone have related but different meanings.
Someone generally refers to an unspecified person.
Someone left a message for you.
Anyone can refer to any person without identifying a particular individual.
Anyone can learn this skill.
Compare the ideas:
Someone can help you.
This suggests that an unspecified person is available or capable of helping.
Anyone can help you.
This suggests that any person could help.
The surrounding context determines which word fits the sentence.
Someone or No One
Someone refers to an unspecified person, while no one means not a single person.
Examples:
Someone answered the phone.
No one answered the phone.
There is also an important spelling point here. No one is normally written as two words in modern standard English.
Therefore, do not assume that all indefinite pronouns containing one follow the same spelling pattern.
Common Someone or Some One Mistakes
Writing Some One to Mean Someone
One of the most common errors is separating someone into two words.
Incorrect for the usual meaning:
Some one is waiting outside.
Correct:
Someone is waiting outside.
If the meaning is some person, use someone.
Using the Wrong Verb
Because someone refers to a person whose identity is unknown, some writers mistakenly use a plural verb.
Incorrect:
Someone are coming to help.
Correct:
Someone is coming to help.
Incorrect:
Someone have left a message.
Correct:
Someone has left a message.
Remember that someone is singular.
Confusing Someone With Anyone
These words can sometimes appear in similar sentences, but their meanings are not identical.
Someone called me.
This means an unspecified person called.
Anyone can call me.
This means any person is able to call.
Choose the word based on the meaning you want to express.
Assuming Someone Always Means a Specific Person
Someone does not identify a particular individual.
For example:
Someone is outside.
The listener knows that an unidentified person is outside, but the sentence does not reveal who that person is.
Someone in Formal Writing
There is no problem with using someone in formal English.
Examples include:
Someone with relevant experience should review the report.
If someone has a question, they can contact the office.
Someone from the management team will respond shortly.
Someone must verify the information before publication.
The word is clear, standard, and widely accepted.
You do not need to replace someone with an unnecessarily complicated expression simply to make your writing sound formal.
Someone in Everyday English
Someone is also very common in casual conversation.
For example:
- Someone is at the door.
- Someone called you.
- Someone took my seat.
- I saw someone outside.
- Someone told me about it.
- I need someone to help.
- Did someone see my keys?
These sentences sound natural because someone is the normal indefinite pronoun for an unspecified person.
How to Remember Someone or Some One
A simple memory trick can help:
If you mean “some person,” use “someone.”
For example:
Some person left this bag.
becomes:
Someone left this bag.
Another example:
Some person is calling you.
becomes:
Someone is calling you.
This rule will solve the vast majority of spelling questions involving someone or some one.
Someone Meaning in Simple English
The simplest definition is:
Someone means some person.
For example:
Someone is knocking.
means:
Some person is knocking.
Another example:
I need someone to help me.
means:
I need some person to help me.
If this substitution makes sense, someone is usually the correct choice.
Someone or Some One: Quick Comparison
| Form | Main use | Example |
|---|---|---|
| someone | An unspecified person | Someone called me. |
| some one | Separate use of some plus one in limited constructions | Some one person must decide. |
For ordinary writing, someone is the form you will use most often.
Frequently Asked Questions
Is someone one word or two words?
Someone is one word when it means an unspecified person. This is the standard form in modern English.
Is some one grammatically correct?
Some one can appear in limited contexts where some and one function separately. It is not normally used when the intended meaning is simply an unspecified person.
Which is correct, someone or some one?
Use someone when you mean some person. The two-word form has a much more limited use.
Can I write some one instead of someone?
Usually not. If your sentence means an unspecified person, write someone as one word.
Is someone a pronoun?
Yes. Someone is an indefinite pronoun because it refers to a person without identifying exactly who that person is.
Is someone singular or plural?
Someone is grammatically singular. It normally takes a singular verb.
Correct:
Someone is here.
Can someone refer to a male or female person?
Yes. Someone does not specify the person’s gender.
Can someone be used in formal writing?
Yes. Someone is completely acceptable in formal, academic, professional, and everyday English.
What is the difference between someone and somebody?
Both words refer to an unspecified person. Someone is a neutral choice that works across many types of writing, while somebody can sound slightly more conversational in certain contexts.
What is the difference between someone and anyone?
Someone usually refers to an unspecified person, while anyone can refer to any person without identifying a particular individual.
What is the opposite of someone?
No one expresses the opposite idea when you mean that not a single person is involved.
Should someone have a singular verb?
Yes. Use a singular verb with someone.
Correct:
Someone has taken my notebook.
Not:
Someone have taken my notebook.
Conclusion
The correct choice in most situations is someone, not some one. When you mean an unspecified person, someone is written as one word and functions as an indefinite pronoun.
For example:
Someone called me.
Someone is waiting outside.
I need someone to help me.
The two-word form some one can appear in limited grammatical constructions where some and one have separate roles, but it is much less common in modern English. In many such cases, a clearer sentence can be created by rewriting the phrase.
The easiest rule to remember is simple: If you mean “some person,” use “someone.” This will help you avoid one of the most common spelling mistakes involving this English word.
I am Charlotte Kensington, an education-focused writer who loves turning complicated ideas into simple and useful information. I write for readers who want to learn something new, improve their study habits, and develop practical skills. At Teachlora, my goal is to provide reliable and reader-friendly educational content that feels useful in real life. My books, A Better Way to Learn and The Curious Learner, explore simple approaches to learning and personal improvement.
Books:
- A Better Way to Learn
- The Curious Learner
Eleanor Whitmore