on

on — preposition

1. touching the top or outer side of something, or moving into that place.

1.介系詞A1
釋義

touching the top or outer side of something, or moving into that place.

例句

The keys are on the kitchen table beside Dad's newspaper.

on + surface noun

Lina dropped her wet towel on the chair by the window.

movement onto a surface

同義詞
  • upon

    more formal and less common in everyday speech

  • onto

    used only for movement into contact, not for a static position

反義詞
  • under

    in a lower position beneath something

  • off

    not touching or no longer on the surface

文法句型

on + surface/body-part noun

put/place/land + on + noun

用法筆記

The noun after 'on' is usually a physical surface or body part. Distinguish from sense 2: this sense is about simple position or movement into contact, while sense 2 often involves covering, wearing, or attachment.

常見錯誤

The keys are in the table.
The keys are on the table.
💡use 'on' when something touches the surface.
Put your bag over the chair.
Put your bag on the chair.
💡'on' is the normal choice for resting on top of a surface.

2. spread across a surface, worn or carried by someone, or fixed to another thing.

2.介系詞A1
釋義

spread across a surface, worn or carried by someone, or fixed to another thing.

例句

Sophie wore a silver ring on her smallest finger.

wear + thing + on + body part

There was mud on the dog's paws after the river walk.

covering a surface

同義詞
  • with

    can describe accompanying features ('a man with a hat'), but not direct surface contact in the same way

  • upon

    formal alternative in some writing, though less natural for clothing or machine parts

反義詞
  • off

    removed from the body, surface, or object

文法句型

wear/have/carry + thing + on + noun

something + on + machine/body/surface noun

用法筆記

Common with clothes, body parts, surfaces, and parts of machines. Distinguish from sense 1: here the thing is often worn, hanging, covering, or attached rather than simply resting in a place.

常見錯誤

She wore a ring in her finger.
She wore a ring on her finger.
💡use 'on' for something attached to a body part.
There was mud at his shoes.
There was mud on his shoes.
💡'on' shows that a substance covers the surface.

3. marking the day, date, or occasion when something happens.

3.介系詞A1
釋義

marking the day, date, or occasion when something happens.

例句

We always eat noodles on Friday nights after basketball practice.

on + day + part of day

Ken's visa ends on 30 June, so he must renew it.

on + date

同義詞
  • during

    works for longer periods, but not usually for exact days or dates

  • at

    used for clock times rather than days or dates

文法句型

on + day/date noun

on + day + part of day

on + special occasion noun

用法筆記

Use this sense with days, dates, and named occasions. Compare 'at' for clock times ('at six') and 'in' for months, years, and longer periods ('in June', 'in winter').

常見錯誤

The meeting is in Monday.
The meeting is on Monday.
💡use 'on' with days.
Her birthday is at 12 May.
Her birthday is on 12 May.
💡dates take 'on', not 'at'.

4. marking the surface where words, numbers, or pictures appear.

4.介系詞A2
釋義

marking the surface where words, numbers, or pictures appear.

例句

Mia drew a red star on the corner of the map.

draw + on + surface

The nurse wrote Daniel's temperature on a paper bracelet.

write + on + surface

文法句型

write/print/draw/sign + on + surface noun

用法筆記

The noun after 'on' is the surface carrying the marks, such as paper, a wall, a sign, a page, or a screen. Distinguish from sense 2: in this sense, the important idea is that information or a picture appears there.

常見錯誤

Please write your name in the form.
Please write your name on the form.
💡use 'on' for the surface that carries the writing.
The number is printed at the box.
The number is printed on the box.
💡'on' shows where the words or numbers appear.

5. marking the vehicle or other means a person uses to move from place to place.

5.介系詞A2
釋義

marking the vehicle or other means a person uses to move from place to place.

例句

We reached the lake on foot because the road was flooded.

fixed phrase: on foot

Nina reads comic books on the bus to school.

on + the + vehicle noun

同義詞
  • by

    names the travel method in a more general way: 'by bus', 'by train'

文法句型

on + the + vehicle noun

on foot

on horseback

on + plural vehicle noun

用法筆記

Use this sense for travel by bus, train, horse, bicycle, and in the fixed phrase 'on foot'. Compare 'by bus' or 'by train', which name the method more generally and not the experience of being on the vehicle.

常見錯誤

We came by foot.
We came on foot.
💡'on foot' is the fixed phrase.
She read on bus.
She read on the bus.
💡with most vehicles in this sense, English normally needs the article.

6. showing that a person or thing is in a temporary state or going through a formal

6.介系詞B1
釋義

showing that a person or thing is in a temporary state or going through a formal or public process.

例句

The garage is on fire, so call the fire station.

be on + dangerous state

Several nurses stayed on duty through the stormy night.

be on + duty

同義詞
  • under

    used in some nearby collocations such as 'under pressure' or 'under repair', but not with the same set of fixed phrases

文法句型

be on + state/process noun

go on strike

be on leave/trial/duty/fire

用法筆記

Usually appears in fixed phrases after 'be', 'go', or 'stay'. The noun after 'on' names the state or process itself, not the thing providing support. Distinguish from sense 15: sense 6 is about being in a condition or action ('on strike', 'on trial'), while sense 15 names what someone or something lives or runs on.

常見錯誤

The nurses were in duty all night.
The nurses were on duty all night.
💡'on duty' is the fixed expression.
The workers made strike.
The workers went on strike.
💡English uses the pattern 'go on strike'.

7. used before a medium or instrument to show what something is recorded, broadcast

7.介系詞A2
釋義

used before a medium or instrument to show what something is recorded, broadcast, or played through.

例句

The interview was recorded on video for the school news website.

recorded on + medium

Lina heard the weather report on the radio before breakfast.

on the radio — broadcast medium

同義詞
  • via

    more formal and mostly for the medium, not for musical instruments

  • with

    can name an instrument or tool, but it does not sound as fixed as 'play on the piano'

文法句型

recorded on + medium noun

play + piece on + musical instrument

用法筆記

The noun after 'on' is usually a medium or instrument: radio, video, film, TV, piano, guitar. Distinguish from sense 4 (WRITING), which marks the surface where words or pictures appear.

常見錯誤

I heard the news in the radio.
I heard the news on the radio.
💡English uses 'on' for broadcast media.
Mika played the song with the violin.
Mika played the song on the violin.
💡use 'on' before the instrument in this pattern.

8. used after a verb of contact to name the thing that hurts or injures you when yo

8.介系詞B2
釋義

used after a verb of contact to name the thing that hurts or injures you when you touch it.

例句

Noah banged his elbow on the bus door this morning.

bang + body part + on + object

Emma cut her finger on a broken jar in the sink.

cut + body part + on + sharp object

文法句型

hit + body part + on + object

cut/scrape + body part + on + sharp object

用法筆記

Usually follows verbs such as hit, bang, cut, bruise, or scrape. The noun after 'on' is often a hard edge, rough surface, or sharp object.

常見錯誤

Lina hit on the table her knee.
Lina hit her knee on the table.
💡put the injured body part before 'on + object'.
Marcus cut his hand by the broken glass.
Marcus cut his hand on the broken glass.
💡use 'on' for accidental injury from contact.

9. in the direction of a person, place, or target, especially when moving at it or

9.介系詞A2
釋義

in the direction of a person, place, or target, especially when moving at it or attacking it.

例句

Before dawn, the soldiers marched on the border town.

march on + place

The rebels opened fire on the bridge from the trees.

fire on + target

同義詞
  • toward

    general direction word; less tied to attack and pressure than this sense

  • against

    often used for hostile action, but it does not cover forward movement toward a place

反義詞
  • away from

    shows movement in the opposite direction

文法句型

verb of movement + on + place

verb of attack + on + target

用法筆記

Most common after verbs of attack or forward movement, such as march, fire, turn, or set. Distinguish from sense 1 (ABOVE), where 'on' describes physical contact with a surface.

常見錯誤

The rebels opened fire to the bridge.
The rebels opened fire on the bridge.
💡the target of attack takes 'on' in this pattern.
The soldiers marched to on the town.
The soldiers marched on the town.
💡do not add 'to' before this use of 'on'.

10. about a particular subject, issue, or area of study.

10.介系詞B1
釋義

about a particular subject, issue, or area of study.

例句

Professor Lin gave a short talk on sea turtles.

talk on + topic

Maya needs your advice on the flat before signing.

advice on + matter

同義詞
  • about

    the closest everyday equivalent

  • concerning

    more formal, especially in writing

文法句型

noun of communication + on + topic

book/paper/talk + on + subject

用法筆記

Common after nouns or verbs of speaking, writing, teaching, and thinking: book on, talk on, opinion on, advice on, lecture on. Distinguish from sense 12, which follows verbs of dependence or basis such as depend on or base on.

常見錯誤

We had a discussion about on the budget.
We had a discussion on the budget.
💡use one preposition, not both.
She wrote a paper for climate change.
She wrote a paper on climate change.
💡after 'paper', 'book', or 'talk', 'on' marks the topic.

11. used after money words or spending verbs to name what the money is paying for.

11.介系詞A2
釋義

used after money words or spending verbs to name what the money is paying for.

例句

Maya spent all her birthday money on art paper.

spend money on + thing

Dad put a deposit on the blue van yesterday.

put a deposit on + purchase

同義詞
  • for

    used with some payment verbs such as 'pay', but not with the fixed pattern 'spend money on'

  • toward

    used when money covers only part of a cost, not the whole spending target

文法句型

spend money on + thing

put a deposit on + purchase

用法筆記

Usually appears after spend, waste, save, or nouns such as money, cost, and deposit. The noun after 'on' is the item, service, or event that receives the payment.

常見錯誤

Maya spent all her birthday money for art paper.
Maya spent all her birthday money on art paper.
💡'spend money' takes 'on' before the thing bought.
Dad put a deposit for the van.
Dad put a deposit on the van.
💡use 'on' after 'deposit' when naming the purchase.

12. used after verbs like depend, rely, or base to show the person, thing, or fact t

12.介系詞
釋義

used after verbs like depend, rely, or base to show the person, thing, or fact that something needs or comes from.

例句

Saturday's match depends on the weather after lunch.

depend on + condition

The twins rely on their aunt for after-school care.

rely on + person

同義詞
  • because of

    shows cause, but it does not express dependence or support as clearly as this sense

  • from

    can mark origin with some verbs, but not with fixed patterns such as 'depend on' or 'based on'

文法句型

depend on + condition/person

rely on + person/thing

base + noun + on + source

用法筆記

Common after depend, rely, base, rest, hang, and hinge. A following clause is often introduced by 'whether' or an -ing form, as in 'depends on whether it rains' or 'depends on Maya arriving early'.

常見錯誤

The trip depends from the weather.
The trip depends on the weather.
💡'depend' takes 'on', not 'from'.
Our plan is based in last year's map.
Our plan is based on last year's map.
💡use 'on' when naming the source or basis.

13. used with a task, case, programme, or project to show that someone has a job or

13.介系詞
釋義

used with a task, case, programme, or project to show that someone has a job or active role there.

例句

Marcus is on the airport case with two senior detectives.

be on + case for active involvement

Three nurses are on night duty during the holiday weekend.

on duty = assigned task

同義詞
  • involved in

    a fuller phrase that states participation more directly

  • working on

    common with projects and cases, but less natural with duties or programmes

  • taking part in

    best for events and activities rather than assigned tasks

反義詞
  • off

    used for duties or schedules when someone is not assigned

  • out of

    used when someone is excluded from an activity or programme

文法句型

be on + case/duty/program

work on + project

stay on + story

用法筆記

Often follows verbs such as 'be', 'work', or 'stay'. The object is usually a task, duty, case, project, programme, or trip rather than a formal organization. Distinguish from sense 17, which is more about membership in an established group.

常見錯誤

Marcus is in the airport case.
Marcus is on the airport case.
💡use 'on' for taking part in a case or task.
Nina worked in the museum project all summer.
Nina worked on the museum project all summer.
💡use 'on' with projects someone is involved in.

14. used before a wage, pension, allowance, or other source of money to show what so

14.介系詞
釋義

used before a wage, pension, allowance, or other source of money to show what someone depends on in order to live.

例句

After the factory closed, the family lived on Mei's small salary.

live on + income source

Grandpa gets by on a farm pension and free meals.

同義詞
  • from

    a neutral source word, but it does not always imply dependence for living

  • off

    informal, especially in phrases like 'live off'

文法句型

live on + salary

survive on + income

be on + scholarship

用法筆記

Usually follows 'live', 'survive', 'get by', or 'be'. The object is a source of money such as a salary, pension, allowance, scholarship, or customer base, not food or fuel; compare sense 15.

常見錯誤

The family lived from Mei's salary.
The family lived on Mei's salary.
💡'on' is the usual preposition for the money you depend on.
Rosa was in a music scholarship.
Rosa was on a music scholarship.
💡say 'on' when a scholarship supports you financially.

15. used before food, fuel, or medicine to show what keeps a person, animal, machine

15.介系詞B2
釋義

used before food, fuel, or medicine to show what keeps a person, animal, machine, or treatment going.

例句

The old bus runs on diesel from a farm station.

run on + fuel

Baby goats can live on milk for several weeks.

同義詞
  • with

    possible with some tools or fuels, but less idiomatic for diet or medicine

  • off

    informal, especially in phrases like 'live off the land'

文法句型

run on + fuel

feed on + food

be on + medicine/diet

用法筆記

Common after 'live', 'feed', 'run', 'work', or 'be'. The object names what provides nourishment, power, or treatment, so it can be food for living things, fuel for machines, or medicine for patients. Distinguish from sense 14, where the support is money.

常見錯誤

The bus runs by diesel.
The bus runs on diesel.
💡use 'on' for the fuel that powers something.
Wild ducks feed from rice left in the fields.
Wild ducks feed on rice left in the fields.
💡'feed on' means eat something regularly.

16. used for a place beside a road, river, coast, wall, or similar line, often follo

16.介系詞B1
釋義

used for a place beside a road, river, coast, wall, or similar line, often following its side.

例句

The Chen family rented a small cabin on the river near Hualien.

on + river = beside it

A row of shops stands on both sides of the road.

on both sides of

同義詞
  • beside

    very close in meaning for nearby position

  • along

    emphasizes following the side or length of something

反義詞
  • away from

    shows separation from the road, river, coast, or other line

文法句型

on + river/coast/beach

on + road/path

on + border

用法筆記

The object is usually a road, river, coast, beach, path, wall, or border, and the subject is often a place located beside it. If one thing is touching the surface of another, use sense 1 or 2 instead.

常見錯誤

Their cabin is in the river near Hualien.
Their cabin is on the river near Hualien.
💡here 'on' means beside the river, not inside it.
Several farms are in the French border.
Several farms lie on the French border.
💡use 'on' for places along a border line.

17. used with a committee, team, jury, or similar group to show that someone belongs

17.介系詞C1
釋義

used with a committee, team, jury, or similar group to show that someone belongs to it as a member.

例句

Aiko serves on the city arts committee this year.

serve on + committee

Two parents sit on the school board this year.

sit on + board

同義詞
  • in

    more neutral for belonging to organizations, but less idiomatic with committees and juries

  • part of

    an explicit phrase for membership, though less compact

反義詞
  • outside

    shows that someone is not included in the group

文法句型

serve on + committee

sit on + board/panel

be on + jury/team

用法筆記

Frequently used after 'be', 'serve', and 'sit'. The object is normally a committee, board, panel, jury, or team with recognized membership. Distinguish from sense 13, which can describe temporary involvement in a task or project.

常見錯誤

Aiko serves in the city arts committee.
Aiko serves on the city arts committee.
💡committees and boards usually take 'on'.
Marcus was in the jury for the robbery trial.
Marcus was on the jury for the robbery trial.
💡the fixed phrase is 'on the jury'.

18. used before a device, instrument, machine, or system to show what someone uses t

18.介系詞B1
釋義

used before a device, instrument, machine, or system to show what someone uses to do something.

例句

Mina booked the tickets on her phone during lunch.

do something on + device

The children learned their first song on the piano.

play or learn on + instrument

同義詞
  • with

    everyday choice for a physical tool, though less common with apps and systems

  • through

    good for platforms and systems, especially online services

文法句型

do/buy/pay on + device or app

play/learn on + instrument

enter on + system

用法筆記

The object is a device, instrument, machine, platform, or system used to do the action. Distinguish from sense 4 when 'on' marks where words or pictures appear, and from sense 7 when it marks the form or medium of a performance or record.

常見錯誤

Mina booked the tickets in her phone.
Mina booked the tickets on her phone.
💡use 'on' for the device or platform used.
The children learned their first song in the piano.
The children learned their first song on the piano.
💡instruments commonly take 'on' here.

19. used with the same noun repeated to show one similar event or thing following an

19.介系詞
釋義

used with the same noun repeated to show one similar event or thing following another.

例句

Loss on loss followed the club through a miserable spring.

repeated noun pattern: loss on loss

Wave on wave crashed against the harbor wall all night.

wave on wave for repeated movement

同義詞
  • after another

    used in phrases such as 'one after another'; less compact than repeating the noun with 'on'

  • repeatedly

    gives the general idea, but it does not create the same stacked pattern

文法句型

loss on loss

wave on wave

day on day

用法筆記

Mostly appears in repeated-noun patterns such as 'loss on loss' and 'wave on wave'. It emphasizes one similar event after another, rather than simple frequency.

常見錯誤

The club lost on and on after April.
The club suffered loss on loss after April.
💡this pattern repeats the noun, not the preposition by itself.

20. used to measure one result, amount, or version against another.

20.介系詞
釋義

used to measure one result, amount, or version against another.

例句

This year's sales are up on last year's even without ads.

up on for comparison with an earlier figure

Mina's second sketch improves on her first one in every way.

improve on + earlier version

同義詞
  • compared with

    more explicit and neutral, especially in formal writing

  • against

    common when figures or results are set beside a standard

文法句型

improve on [thing]

up on [earlier figure]

down on [earlier figure]

用法筆記

Most common after verbs such as 'improve' or with phrases like 'up on' and 'down on'. Distinguish from sense 10, where 'on' shows topic or relation rather than a direct comparison.

常見錯誤

This year's sales are up than last year's.
This year's sales are up on last year's.
💡in this pattern, 'on' introduces the thing you compare with.

21. used to say that someone has an item physically with them, for example in a pock

21.介系詞C2
釋義

used to say that someone has an item physically with them, for example in a pocket, wallet, or handbag.

例句

Do you have any cash on you for the night market?

have + thing + on you

Rosa never keeps her passport on her during school trips.

keep + item + on her

文法句型

have [thing] on me

have [thing] on you

keep [thing] on + pronoun

用法筆記

Usually follows 'have', 'keep', or 'carry', and the object after 'on' is normally a person pronoun such as 'me', 'you', or 'her'. It points to things physically with the person, not things they own in general.

常見錯誤

I don't have my card on myself.
I don't have my card on me.
💡this pattern normally uses object pronouns like 'me', 'you', and 'him'.

22. used before an event or piece of information that another action follows from, o

22.介系詞
釋義

used before an event or piece of information that another action follows from, often both later in time and because of it.

例句

On hearing the fire bell, the cooks ran into the street.

on + -ing for action after a trigger

On losing their father, the twins moved in with Aunt May.

同義詞
  • after

    gives the time order, but it often lacks the same idea of cause

  • following

    more formal and common before noun phrases

文法句型

act on [information]

on hearing [news]

on returning [place]

用法筆記

Often appears in phrases like 'on hearing...' or after verbs such as 'act'. The event after 'on' is usually the trigger for what happens next, unlike sense 3, which only marks time.

常見錯誤

On hear the bell, the boys ran out.
On hearing the bell, the boys ran out.
💡after 'on' here, use a noun phrase or an -ing form.

23. used after a person or organization to mark who pays the bill or cost.

23.介系詞
釋義

used after a person or organization to mark who pays the bill or cost.

例句

Don't reach for your wallet; lunch is on me today.

be on + person paying

The repairs were on the landlord after the pipe burst.

同義詞
  • paid by

    a more explicit passive phrase for the same payer idea

  • at [someone's] expense

    more formal and often used in writing rather than casual offers

文法句型

be on me

be on [person/company]

on public insurance

用法筆記

Most common after 'be', especially in short offers such as 'It's on me.' The noun after 'on' names the person or group paying, not the thing being bought.

常見錯誤

Lunch is on I today.
Lunch is on me today.
💡after a preposition, use the object pronoun 'me', not 'I'.

24. used after the affected person to show who is left in trouble when something sud

24.介系詞
釋義

used after the affected person to show who is left in trouble when something suddenly stops working properly.

例句

My old laptop froze on me during the class talk.

verb of failure + on + affected person

The rental car broke down on us outside Hsinchu.

break down on + person

同義詞
  • let [person] down

    broader and often figurative; it can describe people as well as machines

文法句型

freeze on [person]

break down on [person]

quit on [person]

用法筆記

Common with verbs for breakdown or sudden failure, such as 'freeze', 'die', 'quit', and 'break down'. The noun or pronoun after 'on' names the unlucky person affected by the problem.

常見錯誤

The printer stopped to me during the test.
The printer stopped on me during the test.
💡use 'on' to show who suffered from the failure.

25. showing how many points a player or team has at that stage of a competition.

25.介系詞
釋義

showing how many points a player or team has at that stage of a competition.

例句

After three rounds, Taiwan Blue are on 18 points.

be on + number + points

Marcus moved into first place when he went on 27 points.

go on + number + points

同義詞
  • with

    used in some reports to state a total, but less fixed than this sports-table pattern

  • having

    can paraphrase the idea, but it does not replace the set 'on + points' pattern

文法句型

be + on + number + points

go/stay/finish/end + on + number + points

用法筆記

Usually follows verbs like 'be', 'go', 'stay', 'finish', or 'end' in sports and competition reports. The phrase after 'on' is normally a number plus 'points'.

常見錯誤

The Tigers are with 12 points.
The Tigers are on 12 points.
💡sports reports use 'on' before a points total.
Lina finished in 18 points.
Lina finished on 18 points.
💡use 'on' for the score someone ends with.

on — adverb

on — adjective

on — noun