An idiom is a fixed or partly fixed expression whose meaning is not simply the literal meaning of its individual words. If someone is “over the moon,” they are delighted, not travelling in space. These 30 idioms appear in British English and will help you understand conversations, stories and informal writing.
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Learn the whole expression, not just the translation
Many of these idioms are also common in other varieties of English. The final group includes expressions particularly associated with British usage, but none should be treated as a test of someone’s nationality. Register matters too: an idiom that works among friends may sound too informal in a technical report.
Learn a short example alongside each meaning. Notice which parts change with the sentence: “I’m pulling your leg” becomes “She was pulling his leg.” Other parts stay fixed, so “a storm in a coffee cup” is not the usual form of “a storm in a teacup.”
Everyday situations and relationships
| No. | Idiom | Meaning | Example |
|---|---|---|---|
| 1 | a piece of cake | Something very easy. | After the practice session, the real task was a piece of cake. |
| 2 | break the ice | Make people feel more relaxed when they first meet. | We played a short game to break the ice. |
| 3 | hit the nail on the head | Identify or describe something exactly. | You hit the nail on the head: the instructions are unclear. |
| 4 | spill the beans | Reveal a secret. | Don’t spill the beans about the surprise party. |
| 5 | let the cat out of the bag | Reveal a secret, often accidentally. | I let the cat out of the bag when I mentioned the tickets. |
| 6 | pull someone’s leg | Joke by trying to make someone believe something untrue. | Relax. I’m pulling your leg about the extra homework. |
Problems, decisions and effort
| No. | Idiom | Meaning | Example |
|---|---|---|---|
| 7 | bite the bullet | Do something difficult or unpleasant that you have been avoiding. | I finally bit the bullet and called to apologise. |
| 8 | get cold feet | Become too nervous to do something you had planned. | She got cold feet before the audition. |
| 9 | be in two minds | Be unable to decide between possibilities. | I’m in two minds about accepting the new job. |
| 10 | sit on the fence | Avoid choosing a side in an argument or decision. | We need your opinion; you can’t sit on the fence forever. |
| 11 | go back to the drawing board | Start planning again because an idea has failed. | The model collapsed, so it was back to the drawing board. |
| 12 | cut corners | Save effort, time or money by skipping necessary steps. | Don’t cut corners when checking the figures. |
Time, money and circumstances
| No. | Idiom | Meaning | Example |
|---|---|---|---|
| 13 | once in a blue moon | Very rarely. | We see our old neighbours once in a blue moon. |
| 14 | at the eleventh hour | At the last possible moment. | They reached an agreement at the eleventh hour. |
| 15 | cost an arm and a leg | Be very expensive. | Repairing that old car cost an arm and a leg. |
| 16 | make ends meet | Have enough money for basic expenses. | They took on extra work to make ends meet. |
| 17 | save for a rainy day | Keep money for a future time of need. | I’m saving part of my wages for a rainy day. |
| 18 | a blessing in disguise | Something that seems bad but later has a helpful result. | Missing that train was a blessing in disguise: I met an old friend. |
Feelings, health and communication
| No. | Idiom | Meaning | Example |
|---|---|---|---|
| 19 | under the weather | Feeling slightly ill. | I’m a bit under the weather, so I’ll stay at home. |
| 20 | over the moon | Extremely happy. | They were over the moon about the new baby. |
| 21 | down in the dumps | Feeling unhappy or discouraged. | He’s been down in the dumps since the trip was cancelled. |
| 22 | get something off your chest | Talk about something that has been worrying you. | I need to get something off my chest about yesterday. |
| 23 | beat about the bush | Avoid saying something directly. | Stop beating about the bush and tell me what happened. |
| 24 | hear something through the grapevine | Learn news informally from other people. | I heard through the grapevine that the shop is moving. |
Expressions with a recognisably British flavour
| No. | Idiom | Meaning | Example |
|---|---|---|---|
| 25 | a storm in a teacup | A lot of anger or worry about a relatively small matter. | The argument over the room number was a storm in a teacup. |
| 26 | throw a spanner in the works | Cause a problem that disrupts a plan. | The rail strike threw a spanner in the works. |
| 27 | not my cup of tea | Not something I enjoy or am interested in. | Horror films aren’t my cup of tea. |
| 28 | the penny drops | Someone finally understands something. | When I saw the diagram, the penny dropped. |
| 29 | Bob’s your uncle | Used informally to mean that the remaining steps are easy and the task is done; sometimes humorous. | Attach the handle, tighten the screws, and Bob’s your uncle. |
| 30 | swings and roundabouts | Gains and losses that roughly balance each other. | The new flat is smaller but nearer work. It’s swings and roundabouts. |
Use the right grammar around an idiom
The verb in an idiom usually changes tense in the normal way. We spill the beans today, but someone spilled the beans yesterday; British English also uses spilt. Similarly, “the penny drops” becomes “the penny dropped” when you describe a past moment of understanding.
Some expressions need a linking verb. Say “I am in two minds” and “She was over the moon,” rather than treating the phrases as independent verbs. With “not my cup of tea,” change the possessive where necessary: “Long meetings aren’t his cup of tea.”
Similar idioms can have different implications
Spill the beans and let the cat out of the bag both involve revealing a secret. The second often suggests an accidental disclosure, although the context is more important than a rigid rule. Neither expression necessarily means telling a lie.
Be in two minds emphasises genuine uncertainty between options. Sit on the fence often suggests that someone is avoiding taking a position, and it can sound critical. Calling another person’s concern “a storm in a teacup” can also sound dismissive, so consider the relationship before using it.
A conversation in context
Maya: Are you applying for the course?
Leo: I’m in two minds. It’s interesting, but it costs an arm and a leg.
Maya: Have you asked about the evening option?
Leo: No. I’ve been beating about the bush instead of calling.
Maya: Ask them today. You might find an option that works.
The expressions add feeling, but the conversation would still be clear without them. Use idioms to express an idea precisely, not simply to make a sentence more complicated. In instructions where misunderstanding would matter, plain language may be the better choice.
Practice: match the situation to an idiom
Choose an expression from the list for each situation. More than one phrase may sound possible in everyday conversation, but the answers below give the closest match.
- You finally understand a joke after someone explains it.
- A speaker avoids saying directly that they disagree.
- A family has just enough money to cover essential expenses.
- You are delighted about being offered a place on a course.
- A broken laptop unexpectedly disrupts your presentation plan.
- A friend is trying to make you believe a silly story as a joke.
Answers and explanations
1. The penny drops: understanding arrives. 2. Beat about the bush: avoid the main point. 3. Make ends meet: cover basic costs.
4. Over the moon: extremely happy. 5. Throw a spanner in the works: disrupt a plan. 6. Pull someone’s leg: tease someone with a joke.
For shorter informal expressions such as chuffed, quid and give me a bell, see our British slang and informal vocabulary guide. Keep idioms in complete example sentences so you remember both their meaning and their grammar. For a dictionary explanation of the final expression, see Collins: swings and roundabouts.
