An idiom is a fixed expression whose meaning cannot be understood from the individual words. When a British person says "it's raining cats and dogs", they don't mean that animals are falling from the sky — they mean it's raining very heavily.
Idioms are a natural part of everyday English. Native speakers use them constantly, often without realising it, in conversation, on TV, in the news, and in workplaces.
She let the cat out of the bag.
= She revealed a secret (not: she released an animal)
This site covers 1,172 British English idioms. They're organised by how often you'll hear them — so you can focus first on the ones that come up every day, then expand your range.
Why learn idioms?
Understanding idioms is essential for:
- Following everyday conversations and TV shows
- Sounding more natural and fluent
- Understanding humour and wordplay
- Cambridge exams (especially C1 and C2 levels)
- Integrating into English-speaking workplaces
Types of Idioms
Not all idioms are equally mysterious. Some are almost impossible to guess; others carry a clue in their imagery.
OPAQUE
The meaning cannot be guessed from the words at all.
"kick the bucket" = to die
TRANSPARENT
The meaning can be guessed from the imagery.
"see the light" = to finally understand
METAPHORICAL
Based on extended metaphor or comparison.
"on the same page" = in agreement
CULTURAL
Tied to history, sport, or British culture.
"bob's your uncle" = and there you are
Related expressions
Idioms overlap with but are distinct from:
Phrasal verbs (e.g. give up, look after) — verb + particle combinations with their own idiomatic meanings. These have their own dedicated page on the site.
Collocations (e.g. heavy rain, make a decision) — words that naturally go together but whose meaning is literal.
Proverbs (e.g. actions speak louder than words) — full sentences offering advice or wisdom. Some proverbs are included here; most collocations are not.
Why Are Idioms Hard?
Idioms create three specific challenges for learners:
1. Non-literal meaning
You can know every word in an idiom and still not understand it. "Break a leg" is friendly, not threatening. "Cost an arm and a leg" has nothing to do with bodies. Direct translation almost always fails.
2. Fixed form
Most idioms can't be changed. You say "by and large", not "large and by". You can "break the ice" but not "shatter the ice". Word order, articles, and prepositions are usually locked in.
✓ spill the beans
✗ spill the peas / pour the beans / spill a bean
3. Register and context
Some idioms are informal ("bricking it"), some are neutral ("a blessing in disguise"), some are old-fashioned ("the bee's knees"), and some are vulgar ("tough shit"). Using the wrong register can sound odd, rude, or dated.
Frequency Tiers
Not all idioms are equally useful. Some you'll hear every day; others you'll encounter once a year in a novel. This site splits the 1,172 idioms into three tiers based on real-world frequency.
VERY COMMON · 178
Heard daily in conversation, TV, news. Master these first.
"a piece of cake", "under the weather", "hit the road"
COMMON · 544
Heard regularly. Expands your range once you know the basics.
"behind closed doors", "blow your own trumpet", "in hot water"
LESS COMMON · 450
Useful to recognise, but less essential for everyday speech.
"a baker's dozen", "fall from grace", "a Trojan horse"
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Study strategy: Aim for active use of Very Common, recognition of Common, and passive awareness of Less Common. You don't need to master all 1,172 — you need to recognise them in context.
Learning Strategies
Learn in context, not in isolation
Don't just memorise "at the eleventh hour". Remember a sentence you heard: "The deal was signed at the eleventh hour." The context anchors the meaning.
Group by theme
Idioms in the same category are often learnt together more easily. Study all the body parts idioms together, or all the weather ones. Use the By Category view to do this.
Start with Very Common
Of the 1,172 idioms on this site, 178 are in daily use. Master those first. Once you can use them confidently, move outward.
Notice them in the wild
Once you've learnt an idiom, you'll suddenly start hearing it everywhere. Keep a small notebook or phone list of idioms you encounter in TV shows, podcasts, and conversations.
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Test yourself: After studying 10 new idioms, close the page and try to recall them. Can you use each one in a sentence of your own?
Register & Formality
Register is about matching your language to the situation. Idioms sit across a wide range of registers, and getting this right matters.
INFORMAL / SPOKEN
Friends, family, casual chat.
"bricking it", "take the mickey", "chill out"
NEUTRAL
Safe in most situations, including work.
"a blessing in disguise", "hit the nail on the head"
FORMAL / WRITTEN
Essays, journalism, speeches.
"a double-edged sword", "the tip of the iceberg"
VULGAR
Only among close friends — avoid at work or in exams.
"take the piss", "a load of bollocks", "tough shit"
British vs American
Most idioms on this site are British English, but many are shared across both varieties. A few differ:
- "touch wood" (UK) vs "knock on wood" (US) — both included here
- "a storm in a teacup" (UK) vs "a tempest in a teapot" (US)
- "throw a spanner in the works" (UK) vs "throw a wrench" (US)
Common Mistakes
Translating literally from your language
Idioms almost never translate. Spanish "no tener pelos en la lengua" (to have no hairs on your tongue) is not said the same way in English. The closest English idioms are "not mince your words" or "speak your mind".
Changing the fixed words
Learners often change an article, preposition, or key noun. The result sounds immediately wrong to a native ear.
✗ "I'll give it the shot"
✓ "I'll give it a shot"
Using the wrong register
Saying "he kicked the bucket" at someone's grandmother's funeral is inappropriate — it's a flippant way to talk about death. Match the register to the situation.
Overusing idioms
Packing every sentence with idioms sounds unnatural. Native speakers use one or two in a conversation, not twenty. Aim for natural flow, not quantity.
Relying on outdated idioms
Some idioms have fallen out of use. Expressions like "the bee's knees" or "skeletons in the closet" are still understood but sound dated to younger speakers.
Top Tips
- Start with the 178 Very Common idioms — these are the ones you'll hear and need to use daily.
- Learn idioms in chunks of 5–10, not in long lists. Spaced repetition beats cramming.
- Always note an example sentence alongside each idiom. The sentence is the memory hook.
- Group by theme (body, weather, animals, food). Related imagery sticks together.
- Say them aloud. Idioms have rhythm — "by and large", "fair and square", "spick and span". Speaking them helps.
- Check the register before using a new idiom in a formal setting. When in doubt, stick to neutral ones.
- Listen actively. Watch British TV (Peep Show, Line of Duty, The Office UK) and you'll hear dozens of idioms per episode.
- Don't translate from your native language. Learn each idiom as a new unit, not a mapping.
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Final thought: You don't need to master all 1,172 idioms. Aim to recognise most, use the common ones confidently, and enjoy spotting the rest in the wild.