study-english

Lessons

What I have learned about my English, grouped by kind. Each entry is a rule with a made-up example — short enough to reread in full.

Articles

a or an follows the sound, not the letter

an goes before a vowel sound. A word starting with a vowel letter can begin with a consonant sound, and the other way round.

user, unit, one-off and European start with a y/w sound, so they take a. Initialisms follow how the letter is said: an SQL query, an HTTP header, a URL.

h cuts both ways, and the silent list is the short one. Only hour, honest, heir and their relatives take an; every h that is actually pronounced takes a — a human, a hotel, a history lesson, a hybrid. A written vowel after the h is not the test.

A singular countable noun needs an article

Korean has no articles, so they are the easiest thing to drop. Almost every singular countable noun needs a, an, the, or a possessive in front of it.

Use the when the listener can identify which one — because it is the only one, or was already mentioned, or is fixed by the context. Use a/an when it is one of several and it does not matter which.

Plurals and uncountable nouns are the exception: Send me the reports or Send me reports are both fine.

Some names still take the

Most proper nouns take no article — Korea, Slack, Kubernetes. The exception is a name for the single thing of its kind rather than a brand: it keeps the.

The same goes for the cloud, the Moon, the Pacific, the Netherlands. A capital letter is not a licence to drop the article.

One catch: when internet means connectivity rather than the network itself, it is an uncountable mass noun, lowercase and with no article — the café has no internet.

the + singular is the normal way to name a kind of thing in general

When a singular noun stands for a whole class rather than one specimen, English prefers the. This is strongest for body parts and organs, species, and instruments. a is not ungrammatical, but it shifts the reading to “some one example”, which is rarely what a general statement means.

A bare plural is the other generic form and is often the most natural of the three: human ears turn vibration into sound. Keep a for when you really do mean any single instance — if a rib breaks, it usually heals on its own.

A stage of the software process takes no article: in CI, in production

CI, production, staging, review and development used as the place where work happens are treated like at school or in bed: no article.

The article comes back with a noun that names one specific thing: the CI run for that commit, the production database, the staging server.

Verb forms

Third person singular takes -s

The -s goes on the verb when the subject is he, she, it, or any single thing — even when a long phrase separates them.

Intransitive verbs have no passive

Some verbs describe something the subject simply does, with nothing done to it. They cannot take be + past participle, however natural the passive feels.

The common ones: expire, occur, happen, arrive, appear, disappear, remain, rise, result, consist.

Noun and verb forms are different words

English often changes the spelling between the noun and the verb, and using one where the other belongs is a grammar error, not a typo. It goes both ways.

The pairs worth memorizing: advice / advise, belief / believe, choice / choose, loss / lose, proof / prove, success / succeed, breath / breathe, belongings / belong.

Some verbs take a person as their object, not a thing

guide, tell, inform, advise, remind, and teach act on a person. What that person receives goes in a second slot, or in a that-clause.

A transitive verb keeps its object, even when the context makes it obvious

Korean drops an object the listener can work out; English keeps it, usually as a pronoun. access, use, enter, install, update and support need something after them. If no object fits, switch to a verb that needs none.

Tense

The present perfect means it is still true

has been describes a state that reaches the present moment. For a state that has already ended, use the simple past — or the past perfect if you are placing it before some other past point.

had been is for a state that ended before another past event: the server had been down for an hour before anyone noticed.

For the same reason the present perfect refuses a definite past time. yesterday, at three, last week, and the question word when all point at a finished moment, so the verb must be simple past.

The other side of the same rule: lately and recently, describing a stretch of time that runs up to now, want the present perfect, not the simple present.

used to says the habit has stopped

used to marks a past habit that is over. Using it for something still true, or for a single recent inconsistency, says the opposite of what is meant.

For a habit that is still in force, use the simple present with always, usually, or normally. To point at one departure from it, name the departure: you normally do X — why not this time?

The simple present says what a thing does; the progressive, what it is doing now

A clause describing what something characteristically or permanently does takes the simple present. is -ing narrows it to this moment, so using it for a fixed property makes a permanent trait sound like a passing state.

Keep the progressive when the point really is “right now”, and the contrast survives: the badge shows unread messages, but it is showing an old count at the moment.

Word order and modifiers

A superlative goes in front of the whole noun phrase

latest, newest, best modify the head noun, so they come before the other words that describe it — not immediately before the head.

Hyphenate a compound modifier before a noun

Two or more words acting as one adjective are joined with a hyphen when they sit in front of the noun, so the reader knows they belong together.

After the noun the hyphen disappears, because there is nothing to disambiguate: the session is logged in, the author is well known.

A noun used in front of another noun stays singular

When a noun works as a modifier — alone or inside a hyphenated compound — it drops its plural, even when the meaning is plural.

The plural returns once the noun is back in its own right: the café welcomes dogs, the child is three years old. A few nouns keep their -s because the singular means something else or does not exist: a sales team, a clothes shop, a news app.

again already contains “this time”

again means the thing has happened one more time, so pairing it with this time says the same thing twice. Drop one of them.

this time too is a different statement — it groups this case with others rather than counting a repeat — and is worth using only when that grouping is the point: the first two builds failed, and this one failed too.

Keep an adverb next to the verb it modifies

An adverb pushed to the end of the sentence, past a phrase it has nothing to do with, attaches itself to whatever it now sits beside. Put it before the trailing phrase instead.

The first reads as though the crash is the automatic part. English binds a modifier to the nearest candidate, so distance from the verb changes the meaning rather than merely sounding odd.

It bites hardest when the trailing phrase is a clause with a verb of its own, because then the stranded adverb lands beside a verb it could plausibly modify and the wrong reading is perfectly grammatical.

Moving the adverb in front of the clause rarely helps either; turn it into an adjective on the thing being produced, or put it before the verb it belongs to.

more goes after the number, not before it

When a number says how many extra things are wanted, the number comes first and more follows it. Putting more in front of the number is ungrammatical.

more does come first when no number follows it — order more chairs, we need more time. The rule is only about the collision with a number, and it holds for the other quantity words too: two fewer chairs, three extra chairs.

What a thing is for takes a relative clause, not a bare -ing modifier

An -ing phrase after a noun says what that particular thing happens to be doing. It does not state what a thing is for, so using it to describe a tool, a product or a role reads as a snapshot rather than a definition.

The -ing form is right when the action really is in progress and is what picks the thing out: the script cleaning the logs right now is the old one.

The -ing phrase also makes the noun the one doing the action. When the noun is a setting where someone else acts — a game, an app, a page — use where or in which, or the thing ends up doing the user’s job.

Prepositions

Things are on a screen or a page, not in it

Use on for a surface or a device: on the screen, on a phone, on a laptop, on a touch screen, on a server. A page is a surface too: on the settings page, on a website, on the dashboard. Use in for something enclosing: in a browser, in an app, in the terminal, in a dialog.

A device that supplies the data takes from, not on

on puts something onto a device’s surface or display. When the device is where the data comes from, the preposition is from — or name the stream it produces and use in.

The same device takes either one, and the choice changes the meaning: show the map on the tablet paints pixels on its screen, while read the map from the tablet pulls the file off it. See [Things are on a screen, not in it] for the display sense, and [Do not chain the same preposition] for keeping from reserved for the real source.

Do not chain the same preposition

Repeating from (or of, or in) down a chain makes each one look like it attaches to the same thing. Use in for the containing relationship and keep from for the actual source.

by names the doer only in the passive, and an instrument only before -ing

by has two jobs and a bare noun after it satisfies neither in an active clause.

As the doer, it works only in the passive. In an active clause the subject is already the doer, so a trailing by X has nothing left to mark and gets read as “by means of X”. When X is the party giving the order, say so with at the direction of, as instructed by, or under, or turn the clause passive.

The same applies to a relative clause: sites that it blocks by the server has to become sites it blocks on the server’s orders.

As the instrument, by needs a gerund, not a bare noun. The means is with X or using X; by marks the method, so what follows it is an action.

by hand, by email, by train look like counterexamples but are fixed idioms: no article, and no substituting a similar noun.

An occasion takes on or in, not with

with names an instrument or a companion. A run, an attempt, a build, or a release is an occasion — when something happened, not what it happened by means of — so it takes on or in.

with returns as soon as the noun really is the means: fix it with a retry.

A platform hosts the work on, not as

as gives a thing a role or a form — publish it as a PDF, ship it as a plugin. The service it is hosted on is a place, not a form, so it takes on, or to for the act of sending it there.

Keep as for the shape the work takes: release it as a single-page site describes what it is, release it on Netlify names where it lives.

Comparison words take as or to, never with

the same, similar, identical, equal each have a fixed partner, and with is not it. with says accompanied by, so it turns a comparison into a description of two things sitting together.

the same as, similar to, identical to, equal to, different from. Only compare takes both, with a difference in meaning: compare X to Y likens them, compare X with Y examines them side by side.

A noun keeps its own preposition

Many nouns are welded to one preposition, and the rest of the sentence does not change it. scope takes of, whatever follows.

The pairs that come up most: the scope of, a reason for, an increase in, a solution to, an answer to, the effect on, a demand for, access to. A fault sits inside what it is a fault of, so a bug, an error and a typo take in:

A relative clause or a question keeps the verb’s preposition

When the object of a preposition becomes the head of a relative clause, the preposition does not disappear with it — it stays behind at the end of the clause. work on a branch still needs its on in the branch you worked on.

Formal writing may move the preposition to the front instead — the library on which he depends — but it has to appear in one place or the other. Dropping it leaves the verb looking transitive and the sentence reads as unfinished.

A question word moved to the front leaves its preposition behind the same way. That includes the by of a passive when the question asks who or what did it.

A booking is made for the people it covers, not with them

with names who is coming along. The number a reservation is sized to is what the booking is for — the same for as in a table for two.

with stays correct when accompaniment really is the point: I travelled with four friends says who came, not how many beds were reserved.

A date range takes one marker, not two

from … to, through, and between … and each mark a span on their own. during marks one too, so putting it in front of another says the same thing twice.

Keep during for a single period — during the outage, during the holidays — and let from … to or through carry a range that names both ends.

A distance from a point is more than N from it, not above N from it

above + a number means “more than” on a scale with no direction of its own: above 30 degrees, above average. A distance measured from a point already has its direction, and above in front of the number adds a second one that clashes with from. Use more than, or let above name the point instead.

A change starts from the next X on, not from a new X

from marks where a change begins, and a starting point is a particular one: the next release, this sprint, Monday. With a, no particular point is named, and from a new X reads as something coming out of an X. Name the point, usually with on after it, or describe every later X instead.

Sentence patterns

Why not takes a bare verb, not -ing

Why not …? is a suggestion and is followed by the plain form of the verb.

To ask for the reason behind something that already happened or is happening, use a full question instead — the two mean different things:

A passive needs a subject the verb can actually act on

Turning a sentence passive moves the object into the subject slot. Put a noun there that the verb does not act on and the sentence describes something that never happens — usually because a different verb is the one that takes that noun.

advance carries a person through the stages; a stage itself opens or unlocks. When a passive feels forced, the fix is usually a different verb rather than a different arrangement of the same one.

Negative purpose is not not to

To say in order that something does not happen, not to alone does not work.

Bare not to is correct only as the object of verbs like tell, ask, or decide: I told him not to wait.

“Unless it is done already” is if not already, not if not yet

The short conditional drops the verb, and only already survives that: if not already. yet needs its negative clause back, with a subject and a verb.

helpful to needs a person; a thing is helpful for -ing

helpful, useful and hard take a to-infinitive only when the subject is a dummy it standing for the whole activity, or when a person is doing the solving. When the subject is the thing that provides the help, name the task with for plus -ing, or drop the adjective and use help.

The same split applies to useful: a useful tool for finding leaks, but it is useful to check for leaks.

A shortened time clause borrows the main clause’s subject

after, once, until, before, when, and while can drop the subject in front of a participle — but the missing subject is then whatever the main clause already has. If that is not what was meant, the sentence quietly attaches the participle to the wrong thing, and in an imperative that wrong thing is you.

An -ing participle behaves the same way, and mismatches there are easier to miss because the phrase sounds complete on its own:

Comparisons trip this most often, and they have a ready-made fix: the main clause’s subject is the thing being compared, so the participle is the passive compared to (or compared with), not the active comparing.

The short form is fine when the subjects genuinely match: once merged, the branch can be deleted works, because the branch is the thing merged.

An imperative tells the reader to act, so name the doer when it is not them

An English imperative has an understood subject, and that subject is always you. When the thing that should perform the action is a program rather than the person reading, a bare imperative points at the wrong actor, and the reader has to guess which was meant.

make X do Y and have X do Y are the two everyday patterns for this; get X to do Y adds a sense of persuading something reluctant. A plain imperative is correct and normal whenever the reader really is the one to act — run the tests before pushing needs no subject at all. The ambiguity appears only when the sentence describes behaviour to be built rather than a task to be done.

A related trap is a participle clause that borrows a subject it should not — see [A shortened time clause borrows the main clause’s subject].

A description must add something to the noun it describes

A modifier that repeats the noun it is attached to tells the reader nothing new: a logging library is already a library that provides logging. Describe the thing by what the name leaves out, which is usually who uses it or what it is for.

The same goes for a relative clause: a scheduler that schedules jobs says half as much as a scheduler that retries failed jobs overnight.

provide takes a thing, not an activity with its own object

provide names what is supplied, so its object is a noun. An -ing phrase that carries an object of its own, such as tracking your workouts, is an activity someone does, and an activity cannot be provided. Say what the thing is for with for plus -ing, say who gets to act with let, or turn the activity into a noun.

A bare -ing word used as a noun is fine after provide — the plan provides hosting — the trouble starts only when it takes an object.

In for X to do, X is the one doing it

for + a noun + a to-infinitive makes that noun the subject of the infinitive: a book for the kids to read means the kids read it. Put a noun there that cannot do the action and the sentence says something odd. When the action belongs to you or to the reader, name them with so … can.

The noun the phrase hangs on is already the infinitive’s object, so that slot stays empty: no it or them for it.

In X is easy to do, X is what gets done

After easy, hard, simple or difficult, the subject is the object of the infinitive: the switch is easy to miss means people miss the switch. So the subject has to be the thing that gets missed, read or done, not the situation around it. Name that thing, or turn the situation into having to ….

worth needs an object: worth it, worth the cost, worth doing

worth behaves like a preposition, so it is always followed by what the thing is worth: a noun, an -ing form, or it for something just mentioned. Ending the clause at worth leaves it unfinished.

The adjective that can stand alone is worthwhile: the trip was worthwhile.

A possessive stands alone when its noun is understood: the other shop's

When a phrase points back to a noun already named, meaning “X’s ones”, keep the 's and drop the noun. Without the 's, X itself becomes one of the things listed or compared: including the finance team puts the team among the late reports.

Countable and uncountable nouns

practice takes no plural in the “training” sense

practice meaning repeated exercise to improve a skill is uncountable, so it never becomes practices.

A plural practices does exist, but it is effectively a different word meaning “customary ways of doing things”: safety practices, hiring practices, best practices. Quantify the uncountable sense with a measure word instead — two hours of practice, a lot of practice.

work meaning effort or tasks takes no plural

work in the sense of labour, or of the tasks someone does, is uncountable, so it never becomes works.

works exists, but as other words: things an artist or writer made (the complete works of Austen), a factory (the gas works), or construction (road works).

difficulty is uncountable when it means “how hard”

In the sense of the level of challenge something presents, difficulty takes no plural. The plural difficulties means troubles, obstacles that were run into — a different sense — so pluralizing it changes the request.

The same split hits experience (know-how vs. individual episodes), damage (harm vs. legal damages) and permission (consent vs. access rights): She asked permission to leave early is uncountable, while file permissions names the settings.

challenge splits the same way: as “how demanding something is” it is uncountable (the puzzle needs more challenge), and the plural names separate tasks or obstacles. To ask for something to be harder, the adjective is usually the most natural: the puzzle should be more challenging.

one stands in for a singular noun; a plural takes ones

The pronoun one repeats a countable noun without naming it again, and it keeps that noun’s number. After a plural, use ones, or make the whole sentence singular.

another takes a singular noun; a plural takes other or more

another is an + other, so it carries the article’s “one” inside it and needs a singular countable noun after it. For several more things, drop the an: other with a plural, or more.

The exception is a number between them, which makes the group one bundle: another two chairs, another three days.

Word choice

An -ally adverb says “with respect to X”, not “in an X way”

Adverbs built from a noun of quality — structurally, categorically, logically — name the dimension a claim is limited to. They do not describe the manner the action should take, so they cannot ask for the quality itself.

The adverb is right when the point really is to restrict a claim to one dimension: the bridge is structurally sound means sound as far as its structure goes, and leaves everything else open.

School years do not translate by number

1st grade, 2nd grade count from the start of elementary school in English, so a Korean-style “high school 1st grade” lands six years off. Name the stage instead, or use the continuous US grade number.

The order is English too: the year comes first, then the school it belongs to. Keeping the Korean order reads as a translation even when the number is right.

freshman, sophomore, junior, senior also work for the four high-school years, but they are US-specific and are used for university years too.

A nationality after be is an adjective, not a plural noun

Most nationality words are both an adjective and a noun. When be is describing who someone is, English takes the adjective, and an adjective has no plural.

The plural noun is for counting people as members of a group: three Koreans joined the call, the Germans on the team. Nationalities ending in -ese and -ish have no singular countable noun at all, so they need a noun after them: a Japanese engineer, a British colleague — never a Japanese.

map of takes a territory; an activity takes guide to or roadmap for

map names a picture of a space, so what follows of is the thing laid out — a place, a field, a system. An activity there is understandable but reads as a mixed metaphor, and English has settled head nouns for that sense.

The other picture nouns behave the same way: a diagram of, a chart of and an atlas of all want the thing, while instructions for, a path to and a plan for want the activity. The test is whether you could point at what follows of — you can point at a repertoire, not at learning one.

conversation is talking; conversion is changing form

The two differ by two letters and both are real words, so a spell-checker passes the wrong one. conversation is people talking; conversion is turning something from one form, unit, or belief into another.

The verbs split the same way: converse is to talk, convert is to change.

Name the skill conversational English, not English conversation

English conversation is the word-for-word form of the Korean name for a speaking course. It is understood, but in running prose it reads as a translated course title: conversation is mostly something you have or hold, not a subject you learn. Put the language in the noun slot instead.

With a verb of doing, the noun is natural: hold a conversation in English, get more conversation practice.

easily is about effort; a clearer explanation is simply

easily says an action takes little effort for whoever performs it. So describe it more easily is about how hard the describing is for the speaker, not how clear the result is for the listener. Ask for the result instead.

easily is right when the effort really is the point: the lid comes off easily, she won the race easily.

a recording is audio or video; a written entry is a record

The verb record covers writing information down, but a countable recording — a recording, your recording, recordings — is heard as captured sound or video. For the written entry say record or note; for the act of writing it down, saving or logging is clearer.

recording is right when there is something to play back: a recording of the lecture, the call recording.

A direction like upwards goes with a verb of motion, not a comparative

upwards, downwards and outwards say which way something moves, so they attach to a verb that moves it: grow, extend, spread, push. A comparative such as taller or wider already names the dimension, and a direction added to it reads as a mismatch.

You save and restore a state, not a status

status is a condition summed up in a word or two, or a progress report: the order status is “shipped”, check the build status. Everything captured at a moment so you can come back to it — every value, position and setting — is the state. Saving, snapshotting and restoring all take state.

status is right for the short answer to “how is it going?”: the status of the deploy, a status update, status: pending.

What comes out of the ground is gems or jewels; jewelry is made from them

jewelry (British jewellery) is the finished things people wear — rings, necklaces, earrings — and is uncountable. What a miner digs up is the raw stone: gems, gemstones, or jewels (countable). So you mine, dig or hunt for gems, and a jeweller turns them into jewelry.

jewel sits in between: a single precious stone, often cut, and also a stone set in jewelry. Treasure covers any of them, finished or not.

proactively means without being asked; actively means with effort

actively is the opposite of passively: doing something with effort, or being engaged in it right now — an actively maintained library, actively looking for a job. It says nothing about who starts it. For acting on your own initiative, before anyone asks, use proactively, or say it plainly: without being asked, unprompted.

fancy means elaborate or upmarket; looking like the real thing is realistic

fancy describes something decorated, elaborate or expensive-looking: a fancy cake, a fancy hotel. It says nothing about being true to life. To ask for something that looks more like the real thing, say realistic or lifelike.

Spelling

Greek rh and th survive in English where Romance spellings drop them

Words English took from Greek keep the h after r and inside th, even though French and Spanish spell the same word without it. Writing the Romance form is a spelling error, not a variant.

The family: rhythm, rhyme, rhetoric, rhapsody, rheumatism, rhinoceros, and the -thm ending in algorithm and logarithm. Note also that rhythm has no vowel between the th and the m, which is what makes it easy to mistype.

Product and platform names keep their capitals in prose

Korean has no capital letters, so the capital on a name is the easiest thing to lose in fast typing. Names of products, platforms, companies and languages are proper nouns: they start with a capital even in the middle of a sentence.

A brand keeps its own spelling, internal capitals included: GitHub, JavaScript, YouTube, PostgreSQL — and a lowercase first letter only where the brand itself has one, as in iPhone and macOS.

Lowercase is right in two places: identifiers such as a folder named android/ or a package name, which follow their own rules; and a common noun that shares the word, as in the robot in the film is an android.

Punctuation

No comma before and when it joins two verbs of the same subject

When and links two actions done by one subject — a compound predicate — no comma goes before it. The comma belongs there only when a second subject starts a second full clause.

An imperative works the same way, because its unstated subject you is shared:

A list of three or more verbs is a different case: there the commas separate the items, as in pull, rebuild, and deploy.

rainy describes the weather; the thing rain makes takes the noun rain

Weather adjectives — rainy, snowy, windy, sunny — describe a time or a place where that weather happens. What the weather itself produces or looks like takes the noun as a modifier instead.

The test is whether the thing has that weather. An afternoon can be rainy; a sound cannot, because the sound is the rain.

A relative clause leaves a gap; it does not repeat the noun as a pronoun

In the X that ... , the noun X is already the missing object or subject inside the clause. Putting a pronoun back in its place says it twice.

Korean fills that slot naturally; English leaves it empty. Read the clause alone — anyone can open ___ — and the gap is where the noun belongs.