20 Expressions with One in English: Meanings & Examples

Hello English learners! Have you noticed how often the word one appears in everyday English? It may be a very small word, but it forms part of many useful expressions, including one by one, one of a kind, from day one and one way or another. In this lesson, you will learn 20 useful expressions with one in English, together with their meanings, usage notes and natural examples.. Many are useful for learners preparing for B2 First and C1 Advanced, although you should always pay attention to whether an expression is neutral, informal or more suitable for spoken English.

Some of these expressions describe how things happen, while others help us talk about people, experiences, agreement, progress and time.

Learning common expressions with one in English can help you understand conversations more easily and make your own English sound more natural and fluent.

Let’s take it one step at a time.

1. One by one

Meaning: individually, one after another

We use one by one when people or things do something separately rather than all at the same time.

• The students entered the room one by one.

2. One of a kind

Meaning: unique; unlike anyone or anything else

We often use this expression to describe someone or something particularly special or unusual.

• The old house is one of a kind and has many original features.

It is particularly common when praising someone or something.

3. The one and only

Meaning: the famous, unique or only person or thing being referred to

This expression is often used for emphasis and can sound humorous or enthusiastic.

• She finally met the one and only actor she had admired since childhood.

4. All in one

Meaning: combining several different functions or features in a single thing

• This device is a printer, scanner and photocopier all in one.

5. One in a million

Meaning: extremely unusual, special or valuable. We commonly use one in a million to describe a person we consider exceptionally good.

• My grandmother is one in a million — she is always there when I need her.

6. For one thing

Meaning: used to introduce one reason, especially when there are other reasons as well

• I wouldn’t move there. For one thing, housing is extremely expensive.

7. At one time

Meaning: at a particular time in the past; formerly

• At one time, this building was a railway station.

Do not confuse it with at the same time, which means simultaneously.

8. At one with

Meaning: feeling completely connected or in harmony with someone or something. It is particularly common in the expression at one with nature.

• She feels at one with nature whenever she walks in the mountains.
• After a few peaceful days by the sea, he felt completely at one with his surroundings.

9. One way or another

Meaning: somehow; by whatever method is necessary

• One way or another, the truth will eventually come out.

It often suggests determination: you do not yet know exactly how something will happen, but you believe it will happen.

10. In one go

Meaning: in a single attempt or without stopping

• He read the whole book in one go.

11. All for one and one for all

Meaning: everyone in a group supports everyone else

• The team believed in the principle of all for one and one for all.

12. From day one

Meaning: from the very beginning

• She has supported the project from day one.

13. One thing leads to another

Meaning: one event causes another event, which then causes something else to happen

• We started talking about travelling, and one thing led to another — before long, we had booked a holiday.

14. Take it one step at a time

Meaning: deal with something gradually rather than trying to do everything at once

• Learning a language takes time, so take it one step at a time.

15. One of those days

Meaning: a day when several annoying or unfortunate things happen

• I missed the bus, forgot my phone and spilt coffee on my shirt. It’s one of those days!

16. As one

Meaning: together and in complete agreement or unity

• The audience stood as one and applauded.

17. At one’s best

Meaning: performing, behaving or feeling as well as possible

• I’m usually at my best early in the morning.

18. Make one’s way

Meaning: move towards a place, often with some effort; sometimes, gradually make progress in life or a career

Moving somewhere

• We made our way through the crowd towards the exit.

Making progress

• He started as an assistant and gradually made his way into management.

19. Pull oneself together

Meaning: regain control of your emotions and behave calmly again

• She was upset at first, but eventually pulled herself together.

20. One and the same

Meaning: exactly the same person or thing, even though they may appear to be different

• The owner and the manager turned out to be one and the same person.

Practice: Expressions with One

Now that you have seen 20 useful expressions with one in English, try completing the sentences below without looking back at the lesson. 

1. I’ve supported this idea __________. I thought it was excellent from the very beginning.
2. Don’t try to solve every problem today. Take it __________.
3. We don’t know how yet, but __________ we’ll find the money.
4. My old English teacher was __________. I’ve never met anyone quite like her.
5. I was late for work, lost my keys and broke my phone. It was __________.
6. Hundreds of people stood __________ to honour the victims.
7. I don’t want to move to the city. __________, the rent is far too high.
8. She read the entire novel __________ because she couldn’t put it down.
9. We thought the director and the owner were different people, but they were actually __________.
10. The children entered the classroom __________.

Answers: 1. from day one, 2. one step at a time, 3. one way or another, 4. one in a million / one of a kind, 5. one of those days, 6. as one, 7. for one thing, 8. in one go / in one sitting, 9. one and the same, 10. one by one

Learn More Natural English Expressions

If you enjoy learning expressions that make your English sound more natural, you may like Say It with Style 2 · B2–C1.

The book teaches advanced English idioms through 30 engaging short stories, with clear explanations and practical exercises to help you understand and use the expressions naturally.

Learning expressions with one in English can make your vocabulary more flexible and natural. Start with three or four expressions that you particularly like and try to use them in your own sentences this week.

Related posts: 

• One and Ones in English: Rules, Examples and Practice 
• 100 Everyday English Idioms 
• 50 Prepositional Phrases Related to Time 
• Reflexive Pronouns in English 
• Idiomatic English for Writing and Speaking 
• B2 First Vocabulary 
• C1 Advanced Vocabulary