# Compounds and Conversion

https://langs123.com/en/english/word-formation/compounds-conversion/
CEFR B2–C2 · 2026-10-19 · CC BY 4.0, langs123 contributors (https://creativecommons.org/licenses/by/4.0/)

> Compounds join two words into one meaning, and conversion gives a word a new class with no change of form. A number in a compound adjective keeps its noun singular: a ten-minute walk, a five-year-old boy.

## Cheatsheet

| Point | Rule | Example |
| --- | --- | --- |
| Compound noun | the last word is the head; the first word narrows it | a bus stop / a swimming pool |
| Compound adjective | a singular noun after a number; a participle after a noun or adverb | a ten-minute walk / home-made jam / a well-known author |
| Conversion | a word changes class with no change of form; endings are regular | I'll email you. / Let's go for a run. |
| Short forms | clippings and blends are words; initialisms take a or an by sound | I go to the gym. / an MP |
| Meaning relation | the first noun gives the material, purpose, place, agent or time | a gold ring / a bus driver |
| Plural modifier | a few modifiers keep a plural form | a sports car / a women's magazine |
| Reduplication | the vowel changes in the repeat; i comes before a or o | zigzag / ping-pong |
| Productive element | an element such as -free, -proof or -led makes new adjectives | a sugar-free drink |
| Binomial | the order is fixed by length, sound or custom | fish and chips / null and void |
| Compound or phrase | a compound takes first-word stress and can mean more than its parts | a ˈblackbird ≠ a black ˈbird |
| Creative conversion | nouns become verbs and phrases become modifiers for one occasion | They gifted us a painting. / an I-told-you-so look |
| Trap | the noun after a number stays singular | a five-year-old boy |

## Form: compound nouns

| Pattern | Compounds | Example |
| --- | --- | --- |
| noun + noun | toothbrush / bus stop / football | We wait at the bus stop. |
| adjective + noun | blackboard / software / shortcut | The teacher wrote on the blackboard. |
| V-ing + noun | swimming pool / washing machine / waiting room | The washing machine is broken. |
| noun + V-ing | sunbathing / babysitting / house-hunting | She earns extra money from babysitting. |
| verb + particle | check-in / breakdown / takeaway (US: takeout) | A breakdown delayed us by an hour. |
| noun + preposition + noun | mother-in-law / editor-in-chief / passer-by | My mother-in-law lives in Leeds. |

- The last word is the head; the first word tells which kind. A toothbrush is a kind of brush.
- Closed, hyphenated and open spellings all occur; the dictionary sets which one a compound takes. bedroom / mother-in-law / post office
- A phrasal verb is two words; the noun made from it is one word or hyphenated. We check in at six. ≠ The check-in desk opens at six.
- Plural of a compound: Plurals. Stress of a compound: Sounds and IPA. Phrasal verbs: Phrasal Verbs.

## Form: compound adjectives

| Pattern | Compounds | Example |
| --- | --- | --- |
| number + hyphen + singular noun | five-year-old / three-course / two-bedroom | We took a ten-minute walk. / They rented a two-bedroom flat (US: apartment). |
| noun + participle | home-made / hand-knitted / man-made | She sells home-made jam. |
| adverb + participle | well-known / hard-working / fast-moving | She is a well-known author. |
| adjective + participle | long-lasting / good-looking / old-fashioned | This paint is long-lasting. |
| noun + adjective | world-famous / lifelong / snow-white | It is a world-famous museum. |

- The noun after a number stays singular in a compound adjective. a five-year-old boy / a three-course meal
- The first word carries the comparison. well-known → better-known / well-known → best-known / good-looking → better-looking
- Hyphens in compound adjectives: Punctuation and Capital Letters. Their place before or after a noun: Adjectives and Adjective Order.

## Compound verbs

| Source | Verbs | Example |
| --- | --- | --- |
| back-formation: a noun compound loses its ending | babysitter → babysit / sightseeing → sightsee / proofreader → proofread | I babysit for my neighbours on Fridays. |
| conversion: a noun compound used as a verb | brainstorm / carpool / kick-start | Let's brainstorm some ideas. |
| two words joined as a verb | spoon-feed / hand-pick / double-check | Please double-check the address. |

- A compound verb inflects like its last word. babysit → babysat / spoon-feed → spoon-fed / kick-start → kick-started

## Conversion

| Direction | Words | Example |
| --- | --- | --- |
| noun → verb | email / text / google / bottle | I'll email you the photos. |
| verb → noun | run / walk / drink / look | Let's go for a run. |
| adjective → verb | calm / clean / empty | Please empty your pockets. |

- A noun made from a verb often follows have, take or go for. have a look / take a walk / go for a swim
- A converted verb takes the regular endings. google → googled / email → emailed / text → texted
- Some noun and verb pairs differ in stress. an ˈincrease ≠ to inˈcrease
- More pairs: Sounds and IPA.

## Shortened words and blends

| Kind | Words | Example |
| --- | --- | --- |
| clipping | influenza → flu / examination → exam / gymnasium → gym / refrigerator → fridge | She is good at maths (US: math). |
| blend | breakfast + lunch → brunch / smoke + fog → smog / motor + hotel → motel / Britain + exit → Brexit | We had brunch at eleven. |
| acronym, said as a word | NATO /ˈneɪtəʊ/ · laser · radar | The laser cut through the metal. |
| initialism, said letter by letter | BBC / UK / FAQ / DVD | The answer is on the FAQ page. |

- Choose a or an by the first sound of an initialism. an MP / an FAQ / a UK visa
- An initialism adds -s with no apostrophe. CD → CDs / MP → MPs
- British style writes an initialism without full stops. BBC / UK / NATO

## Meaning relations in noun compounds

| Relation | Compound | Paraphrase |
| --- | --- | --- |
| material | a gold ring | a ring made of gold |
| purpose | a tea cup | a cup for tea |
| place | the city centre (US: city center) | the centre of the city |
| agent | a bus driver | a person who drives buses |
| time | morning coffee | coffee in the morning |
| topic | a history book | a book about history |

| Compound | One reading | Another reading |
| --- | --- | --- |
| a French teacher | a teacher of French | a teacher from France |
| a Chinese restaurant owner | the owner of a Chinese restaurant | an owner who is Chinese |

- Context, and in speech stress, shows which reading is meant.
- Break a long chain with a preposition, so that each noun has one job. a student exam preparation course ≠ a course to prepare students for exams
- A compound names a kind; 's or of names an owner or a whole. a bus ticket / the manager's office / the roof of the house
- Owner or whole: Possessive 's.

## Noun modifiers that keep a plural

| Kind | Compounds | Example |
| --- | --- | --- |
| a plural that names a class | sports car / clothes shop / goods train | He drives a sports car. |
| a plural with its own meaning | savings account / arms race / customs officer | She opened a savings account last year. |
| an irregular plural with 's | women's magazine / men's shoes / children's book | She reads a women's magazine on the train. |

- The plural names a whole class or set, and the head noun can still be plural. a sports car / two sports cars
- The 's of a classifying modifier: Possessive 's.

## Reduplication

| Kind | Words | Example |
| --- | --- | --- |
| the same word twice | hush-hush / so-so / no-no | The deal is hush-hush. / The food was so-so. |
| a change of vowel | flip-flop / tick-tock / zigzag / ping-pong | The clock went tick-tock. / We played ping-pong after lunch. |
| a rhyme | hocus-pocus / razzle-dazzle / willy-nilly | The magician said hocus-pocus. / Don't spend money willy-nilly. |

- With a change of vowel, i comes first and a or o follows. zigzag / ping-pong / tick-tock
- Reduplications are informal and often imitate a sound or a movement. The tap went drip-drop all night.

## Productive second elements

| Element | Meaning | Example |
| --- | --- | --- |
| -free | without | a sugar-free drink |
| -proof | protected against | a waterproof coat |
| -friendly | good or safe for | a child-friendly café |
| -led | directed by | a teacher-led class |
| -based | centred on | a home-based job |
| -related | connected with | a stress-related illness |
| -wise | as regards, informal | Money-wise, we are fine. |
| -minded | with that attitude | an open-minded manager |
| -like | similar to | She moved with catlike grace. |
| -worthy | deserving of | It is a newsworthy story. |

- A hyphen binds each compound in a chain of modifiers before a noun. a low-cost, family-run hotel
- Two compounds that share their last part leave the first with a hanging hyphen. a two- or three-bedroom flat (US: apartment)

## Frozen binomials

| Order set by | Binomials | Example |
| --- | --- | --- |
| the shorter word first | salt and pepper / bed and breakfast / time and money | Pass the salt and pepper, please. |
| the higher vowel first | this and that / in and out / give and take | There was a lot of give and take in the talks. |
| custom | fish and chips / black and white / ladies and gentlemen | We had fish and chips by the sea. / Good evening, ladies and gentlemen. |
| a legal pair of near-synonyms | aid and abet / cease and desist / null and void | The contract is now null and void. |

- A frozen binomial keeps its order in every sentence. It was a matter of life and death.

## Headless compounds

| Pattern | Compounds | Example |
| --- | --- | --- |
| adjective + noun | redhead / paperback / greenhorn | She is a redhead. |
| verb + noun | pickpocket / scarecrow / killjoy / turncoat | The pickpocket ran off with my wallet. |
| adjective + plural noun | lazybones / smarty-pants | Get up, you lazybones! |

- The head lies outside the compound: a redhead names the person who has red hair. A redhead sat beside me.

## Compare: compound and phrase

| Point | Compound | Phrase |
| --- | --- | --- |
| Meaning | a blackbird (= a kind of bird) | a black bird (= any bird that is black) |
| Stress | a ˈblackbird | a black ˈbird |
| Degree word | the first part takes none | a very black bird |
| Idiom | a hot dog (= a sausage in a bun) | a hot dog (= a dog that is hot) |

- The meaning of a compound can lie beyond its parts: butterfly names an insect. A butterfly landed on the flower.
- Stress in compounds: Sounds and IPA.

## Creative conversion

| Kind | Where | Example |
| --- | --- | --- |
| a noun used as a verb | social media, business and sport | Do you friend people you have never met? / They gifted the museum a painting. / She medalled (US: medaled) in the 200 metres. |
| a phrase used as a modifier | journalism | His I-told-you-so smile annoyed her. |
| a phrase used as a modifier | advertising | Taste the fresh-from-the-oven difference. |

- A nonce compound serves one occasion, and hyphens bind its words into one modifier.

## Typical errors

| ✗ | ✓ | Rule |
| --- | --- | --- |
| a ten-minutes walk | a ten-minute walk | the noun after a number stays singular |
| She sells home-make jam. | She sells home-made jam. | the second part is a participle |
| He babysitted the children. | He babysat the children. | a compound verb inflects like its last word |
| a MP | an MP | the first sound of MP is a vowel, so it takes an |
| two CD's | two CDs | an initialism takes -s with no apostrophe |
| a saving account | a savings account | this modifier keeps its plural form |
| a woman magazine | a women's magazine | an irregular plural takes 's as a modifier |
| a two or three bedroom flat | a two- or three-bedroom flat | a hanging hyphen shows the shared last part |
| a teacher-lead class | a teacher-led class | -led is the participle of lead |
| chips and fish | fish and chips | a frozen binomial keeps its order |
| gentlemen and ladies | ladies and gentlemen | the greeting keeps its order |
| a very blackbird | a very black bird | only the phrase takes a degree word |