# one

/ˈwən/ (US) · /wˈɒn/ (UK)

Source: https://englishreference.com/word/one
Updated: 2026-06-19

## Senses

### 1. the number 1

numeral · CEFR A1

the number 1, which comes before 2.

For teachers: the first positive integer in the set of natural numbers; the cardinal number represented by the Arabic numeral 1.

- I have one brother and two sisters.
- The mathematician explained that one is the identity element for multiplication in any standard ring structure.

### 3. people in general

pronoun · CEFR B2 · Formal

any person or people in general.

For teachers: an impersonal pronoun used to refer to people in general, including the speaker.

- One should always be polite to their neighbors.
- One must consider the ethical implications before embarking on such a radical course of action.

Usage: In modern English, 'you' is much more common than 'one' for this meaning.

### 4. a special person

noun · CEFR B1 · Informal

the perfect person for a romantic relationship.

For teachers: a person regarded as a uniquely suitable romantic partner.

- After three years of dating, he finally realized she was the one.
- Despite several failed relationships, she remained optimistic that she would eventually find the one.

### 5. only or single

adjective · CEFR A2

being the only person or thing of a particular type.

For teachers: functioning as a determiner or adjective to indicate a single or sole entity.

- He is the one person I can truly trust with a secret.
- The CEO remained the one individual capable of uniting the board during the hostile takeover bid.

### 6. a certain time

adjective · CEFR B1

used to talk about a specific time in the past or future.

For teachers: referring to a particular but unspecified time or occasion.

- One day, I hope to travel all around the world.
- One evening, quite unexpectedly, a letter arrived that would change the course of his professional life forever.

## Examples

- The baby is one year old.
- There is only one cookie left in the jar.
- Of all the candidates, she is the one most likely to succeed.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.