Idioms and Phrases in the 21st Century

Language dates us.

Not because old language is automatically wrong.

Because words and phrases carry traces of the people, places, technologies and habits that produced them.

This was the central idea of the original 2014 article Idioms and Phrases in the 21st Century.

It argued that a writer should pay attention to whether a phrase feels contemporary, archaic, youthful, formal or attached to an older generation.

That idea was good.

It was also too small.

In 2026, the better question is:

How does a student choose language that belongs to the right speaker, audience, place, time and purpose?

That is what this page now owns.

What is an idiom?

Oxford Learner’s Dictionaries defines an idiom as a group of words whose meaning differs from the meanings of the individual words. Cambridge gives the same basic idea: an idiom is a fixed group of words with a particular meaning that cannot be worked out simply by reading each word literally.

For example:

let the cat out of the bag;
bite off more than you can chew;
hit the nail on the head;
under the weather.

These expressions carry meanings beyond their literal words.

Useful references: Oxford Learner’s Dictionaries — idiom and Cambridge Dictionary — idiom.

But not every useful phrase is an idiom

The 2014 page mixed idioms with ordinary phrases and conversational expressions.

That is common.

Students are often given “idiom lists” that actually contain several different kinds of language.

Idiom: meaning is figurative or non-literal.
Collocation: words naturally occur together, such as heavy rain or make a decision.
Phrasal verb: verb plus particle, such as give up, carry on or look into.
Discourse phrase: language that organises communication, such as in summary or on the other hand.
Slang: informal group language that may be temporary or socially marked.
Fixed expression: a conventional phrase that may be literal but is still learned as a unit.

Why does this distinction matter?

Because the student should know what kind of language tool is being used.

A phrasal verb can sound natural in ordinary dialogue.

A rare proverb may sound formal or old-fashioned.

A slang expression may belong to one age group and be completely wrong for another character.

The real problem is register

A student already changes register naturally in everyday life.

You do not normally speak to a principal exactly as you speak to a sibling.

You do not usually write a formal email exactly like a group chat.

You do not give a scientific explanation with the same vocabulary as a joke.

Good language is not merely correct language. It is language correctly matched to the receiver and situation.

MOE’s current English Language Syllabus 2020 makes the same larger point. It describes language as a system used for different purposes, audiences, contexts and cultures, and emphasises internationally acceptable standard English while recognising changing contexts of language use in Singapore. MOE — English Language Syllabus 2020 (Primary).

A phrase can be grammatically correct and socially wrong

Imagine a Primary 6 composition.

A ten-year-old character receives a message from a friend.

The character replies:

“I am most obliged to you for your correspondence.”

There is nothing grammatically impossible about the sentence.

It is probably the wrong voice.

Now imagine an elderly barrister in a historical novel saying:

“Bro, chill.”

Again, the grammar is simple.

The character signal is wrong unless the writer has a deliberate reason.

This is why idioms and phrases are powerful.

They carry social information.

Language has timestamps

Some expressions survive for centuries.

Others flare brightly for a few years and disappear.

Some return ironically.

Others move from youth slang into ordinary adult speech.

This happens because language is a population system.

People hear an expression.

They repeat it.

They adapt it.

Other groups adopt it.

Media amplifies it.

Then usage stabilises, changes or fades.

Language changes because communities keep remixing it.

Digital communication accelerated the remix

In earlier eras, expressions travelled through family, neighbourhood, school, books, radio, television and film.

Now phrases can travel through:

messaging platforms;
memes;
video clips;
gaming communities;
streaming;
social media;
fan communities;
global workplaces; and
AI-mediated communication.

A phrase can cross countries before older dictionaries record it.

This makes contemporary English richer.

It also makes context more important.

Global English does not belong to one single social group

Oxford notes that English is now a global language used across many countries and communities.

That means students encounter different Englishes.

Singapore English;
British English;
American English;
Australian English;
Indian English;
regional and professional varieties;
formal standard English;
internet English.

A phrase that sounds completely ordinary in one community may sound unusual in another.

Good learners do not respond by declaring one whole community “wrong”.

They learn to distinguish:

what is acceptable in formal school writing;
what is natural in dialogue;
what is local and culturally meaningful;
what may confuse an international audience;
what is slang; and
what is simply an error.

Singapore makes register especially visible

Singapore students often move between several linguistic environments in one day.

Home speech.

School English.

Mother Tongue.

Informal Singlish.

Formal presentation English.

Gaming or internet language.

This can become an advantage.

The student learns that language choice changes with receiver.

That is advanced communicative awareness.

Standard English is not the enemy of character voice

School writing needs internationally acceptable standard English for clarity and assessment.

That does not mean every fictional character has to speak in one sterile voice.

A writer can show age, relationship, mood and social position through dialogue while keeping the narrative controlled.

The distinction is useful:

Narrative control: clear standard English.
Character voice: selective variation where it serves the story.
Formal task writing: register matched closely to audience and purpose.

Voice should be intentional, not accidental.

The 2014 phrase list: what still works?

The original page listed expressions such as:

take things easy;
suck it up;
keep in touch;
speak of the devil;
send me up the wall;
you got me;
hit it off;
mixed up in;
in summary.

Some are still perfectly ordinary.

Some are not idioms at all.

Some are strongly informal.

The lesson is not “delete anything old”.

The lesson is:

know what the expression is doing before you use it.

A living expression has at least five coordinates

Meaning: what does it actually communicate?
Register: formal, neutral, informal, slang?
Community: who uses it naturally?
Time: contemporary, enduring, dated, historical?
Receiver: will this audience understand it as intended?

This is a useful way to study phrases.

Not as dead entries in a list.

As language with coordinates.

Idioms can increase information density

An idiom can compress a familiar human situation into a small phrase.

Bite off more than you can chew compresses the idea of attempting more than one can realistically manage.

Hit the nail on the head compresses the idea of identifying the exact issue.

This compression makes language vivid.

But compression works only if the receiver already knows the code.

An idiom saves words only when the audience can decompress it.

This is why idioms can create problems for language learners

A literal reader may understand every individual word and still misunderstand the sentence.

This becomes especially important in:

comprehension passages;
dialogue;
fiction;
news commentary;
advertising;
humour;
film and television; and
translation between languages.

The student has to notice that literal interpretation fails and search for a conventional meaning.

Translation exposes the cultural layer

Idioms rarely map perfectly word-for-word across languages.

One language may use an animal metaphor.

Another may use weather.

A third may express the same idea directly.

The correct translation job is therefore not:

word → word.

It is:

meaning → function → register → culturally workable expression.

This is one reason idioms are excellent material for teaching how language carries culture.

Do not force idioms into composition

Students sometimes receive advice such as “use five idioms in every composition”.

That can produce unnatural writing.

Imagine a story in which every paragraph contains a proverb, simile and idiom.

The writing begins to sound like a display cabinet.

Use an idiom when it does one of these jobs:

makes a character sound natural;
compresses a familiar idea;
adds humour;
shows attitude;
fits the social setting; or
makes a sentence clearer or more memorable.

If the phrase exists only because the student wants to impress the examiner, it may be doing the wrong job.

A character’s vocabulary is part of character design

Writers design characters through actions, decisions and language.

Ask:

How old is the person?
Where did they grow up?
Who are they speaking to?
How educated are they in this context?
Are they trying to impress, comfort, threaten or joke?
Is the scene formal or intimate?
What year is the story set in?

The answer changes the language palette.

This was the strongest instinct in the 2014 page, and it remains true.

Historical fiction has the opposite problem

A writer can accidentally place modern slang in the mouth of a character living decades earlier.

This breaks the illusion of time.

But historical authenticity does not require unreadable imitation of old language.

The writer balances:

period flavour;
reader comprehension;
character consistency; and
modern readability.

Again, this is receiver design.

Formal writing needs fewer idioms than dialogue

In formal school or academic writing, figurative expressions should be used carefully.

A formal explanation usually benefits from precision.

Compare:

The policy opened a can of worms.

with:

The policy created several unintended secondary problems.

The first may be vivid.

The second is more exact.

The best choice depends on genre and receiver.

Phrasal verbs are often more useful than rare idioms

Natural English depends heavily on ordinary multi-word expressions.

carry on;
find out;
give up;
look after;
run into;
work out;
pick up;
turn down.

These may not look sophisticated.

They make language sound natural.

A learner who knows only difficult single words can still sound unnatural if common phrase patterns are missing.

Collocations are the hidden grammar of vocabulary

Words have preferred neighbours.

English speakers usually say:

heavy rain, not normally strong rain;
make a decision, not normally do a decision;
deeply concerned;
strong evidence;
take responsibility.

These patterns are not always logical from dictionary definitions alone.

They are learned through exposure.

This is why extensive reading matters.

The student should collect phrases, not only words

When learning a new word, record its common company.

Instead of:

reluctant = unwilling

build:

reluctant to admit;
reluctant to leave;
initially reluctant;
a reluctant participant.

This creates usable language chunks.

It also makes composition more natural because the student is not inventing combinations from scratch.

A four-part phrase-learning cycle

Notice: encounter the expression in authentic reading or listening.
Decode: understand meaning, register and context.
Retrieve: recall the expression without copying.
Use: place it naturally into a new sentence, dialogue or paragraph.

A fifth stage follows later:

Reject it when it does not fit.

That final judgement is language maturity.

How to test whether an idiom belongs in a sentence

Would this speaker naturally know the expression?
Would the receiver understand it?
Does it match the level of formality?
Does it add precision, voice or effect?
Does the sentence become worse if the idiom is removed?

If the answer to the fifth question is no, the idiom may be decorative clutter.

Do not treat “modern” as automatically better

The original 2014 article encouraged students to modernise their writing.

That can be useful for a contemporary story.

But modern slang can age faster than a well-chosen older idiom.

Some old phrases survive because they remain useful.

Some new phrases disappear because they were attached to one meme, platform or moment.

The goal is not fashionable writing. The goal is believable writing.

Humour is especially sensitive to time and group membership

Humour often depends on shared cultural knowledge.

A phrase may be funny because everyone recognises the reference.

Ten years later, the reference may vanish.

This is why a student should be careful with meme language in formal school writing.

It can be excellent dialogue.

It can also become incomprehensible very quickly.

Idioms are also evidence about history

Expressions preserve old technologies and social worlds.

We still use phrases whose literal environments are no longer central to modern life.

That makes idioms a form of linguistic archaeology.

Ask of any old expression:

What world produced this metaphor?
Why did the phrase become memorable?
How did the figurative meaning survive after the original context faded?

This turns vocabulary into history.

A composition exercise: write the same scene three ways

Take one event: a student arrives late for an important meeting.

Write the dialogue for:

two close friends;
a student speaking to a teacher;
a character in a formal historical setting.

The event is identical.

The register should change.

This exercise teaches more about idioms than memorising twenty isolated phrases.

A comprehension exercise: translate the figurative back into plain English

When an idiom appears in a passage, ask the student to rewrite it in plain English.

If the student cannot do this, the phrase is not truly understood.

Then reverse the task.

Give the plain meaning and ask for an appropriate idiomatic expression.

This builds two-way control.

An idiom should never outrank meaning

Students sometimes preserve a phrase even when it distorts the sentence.

That reverses the hierarchy.

The hierarchy should be:

meaning → receiver → register → wording.

The phrase serves the meaning.

Not the other way round.

What progress looks like in phrase control

The student distinguishes idioms from phrasal verbs and ordinary phrases.
Expressions are used in the right social context.
Character dialogue becomes more differentiated.
Formal writing becomes less conversational where precision is needed.
Unfamiliar idioms are interpreted through context rather than literally.
Vocabulary notebooks record collocations and chunks, not definitions alone.
The student can explain why a phrase sounds dated, informal or inappropriate.
Fewer idioms are forced into composition for display.

This is not “using more phrases”.

It is having more control over them.

Frequently asked questions

Should Primary students memorise idiom lists?

Lists can provide exposure, but isolated memorisation is not enough. Students need meaning, register, authentic examples and opportunities to retrieve and use the expression appropriately.

Do idioms improve composition marks?

Not automatically. An idiom can strengthen voice or precision when it fits. Forced or inaccurate idioms can make writing less natural.

Is slang bad English?

Slang is informal group language. It can be completely natural in the right community and inappropriate in formal writing. Register matters.

Can Singlish appear in composition?

School writing should maintain standard English control. Selective local speech may sometimes serve character dialogue, but it should be deliberate, understandable and appropriate to the task rather than leaking unintentionally into narration.

How do I know whether a phrase is outdated?

Check current dictionaries, contemporary reading and real usage. Also ask whether the phrase is merely less common or actually inappropriate. Old does not automatically mean unusable.

Are phrasal verbs less sophisticated than difficult vocabulary?

No. Phrasal verbs are a major part of natural English. Sophistication comes from precise control, not from choosing the longest available word.

The 21st-century lesson is not “use newer idioms”

That was the early version of the idea.

The stronger lesson is:

Language is alive, and good writers know where their language is standing.

Every phrase has a history.

A community.

A level of formality.

A likely receiver.

A useful lifespan.

The writer’s job is not to chase whatever sounds newest.

It is to choose the expression that loses the least meaning between speaker and reader.

Sources and further routes

Historical note: first published in November 2014 by Wong Kin Leong as a short note on keeping composition phrases contemporary. Rebuilt in 2026 to preserve that original idea while expanding it into a guide to idiom, phrase type, register, character voice, language change and receiver-aware English.