at

/ət/ (bre, ipa) · [ˈæt] /ət/ (ame, ipa) · [ˈæt] /ət, ˈat/ (ame, mw)

at — 介系詞

1. marks the specific point or place where someone or something is, where something

1.介系詞A1
釋義

在

表示確切地點或工作學習處

marks the specific point or place where someone or something is, where something happens, or where a person works or studies.

例句

The keys are at the front desk beside the blue lamp.

鑰匙在前台藍色檯燈旁邊。

at + exact place

Nina works at the city library near Central Station.

Nina 在中央車站附近的市立圖書館工作。

at + workplace

同義詞
  • in

    used for being inside an area or space, not just at a point.

  • on

    used for a surface, not a general location point.

  • by

    means near something, but not necessarily at the exact place.

文法句型

at + place

at + workplace or school

用法筆記

Often used for a point, event location, workplace, or school that English treats as a specific place. Compare with 'in' when the focus is being inside a larger area rather than at a point.

常見錯誤

❌My aunt works in the hospital reception desk.
✅My aunt works at the hospital reception desk.
💡use 'at' for a specific point or work location.

2. marks the exact time, age, or other precise moment when something happens.

2.介系詞A1
釋義

在…時

表示確切時間或年齡

marks the exact time, age, or other precise moment when something happens.

例句

The store opens at 9:30 sharp on Saturday mornings.

那家店週六早上九點半準時開門。

at + clock time

Lena left home at noon to catch the train.

Lena 在中午離家去趕火車。

同義詞
  • on

    used for days or dates, not exact times.

  • in

    used for longer time periods such as months or years.

  • by

    means no later than a time, not exactly at that time.

文法句型

at + clock time

at + age

用法筆記

Used for points in time such as hours, noon, midnight, and ages. Compare with 'on' for days and dates, and 'in' for months, years, and longer periods.

常見錯誤

❌The meeting starts in 3:00.
✅The meeting starts at 3:00.
💡use 'at' for an exact clock time.

3. used before the person or thing that an action, look, or feeling is directed tow

3.介系詞A1
釋義

朝著；對著

表示動作對著某人或某物

used before the person or thing that an action, look, or feeling is directed toward.

例句

The toddler laughed and waved at the clown.

那個幼童笑著朝著小丑揮手。

verb + at + person

Rico threw the wet towel at the bathroom door.

Rico 把濕毛巾丟向浴室門。

同義詞
  • toward

    often stresses movement or direction, especially over a distance.

  • to

    used with many verbs, but not with patterns like 'look at' or 'smile at'.

  • against

    used when something hits or presses on a surface, not just in its direction.

文法句型

verb + at + person or thing

用法筆記

Common after verbs such as look, stare, smile, wave, throw, bark, and shout. It shows the target of the action rather than a static place, unlike sense 1.

常見錯誤

❌The baby smiled to the nurse.
✅The baby smiled at the nurse.
💡use 'at' when the action is directed toward a person.

4. used after an adjective to name the thing that produces a feeling or reaction.

4.介系詞A2
釋義

因為

表示情緒或反應的原因

used after an adjective to name the thing that produces a feeling or reaction.

例句

Ella was shocked at the price of the tiny cake.

Ella 因為那塊小蛋糕的價格而很震驚。

adjective + at + cause of feeling

The coach grew angry at the team's lazy passing.

教練因為球隊懶散的傳球而生氣。

同義詞
  • by

    often appears with passives such as 'amazed by', but not all feeling adjectives use it.

  • about

    can show a topic of feeling, but not the same fixed pattern as 'angry at' or 'shocked at'.

  • from

    shows source or result in some patterns, not the usual choice after these adjectives.

文法句型

adjective + at + cause

用法筆記

Only used after adjectives or adjective-like expressions of feeling or reaction. Distinguish from sense 5: this sense gives the reason for the feeling, not the activity someone is skilled at.

常見錯誤

❌She was surprised for the news.
✅She was surprised at the news.
💡many feeling adjectives take 'at' before the cause.

5. used after an adjective to name the task, subject, or action someone is judged b

5.介系詞B1
釋義

在…方面

表示擅長或不擅長的項目

used after an adjective to name the task, subject, or action someone is judged by doing well, badly, quickly, or slowly.

例句

Jin is good at fixing old bikes in the garage.

Jin 很擅長在車庫裡修理舊腳踏車。

good at + activity

Marisol was quick at spotting mistakes on the map.

Marisol 在地圖上找錯誤這方面反應很快。

同義詞
  • in

    appears in a few fixed expressions, but 'at' is the usual choice after good, bad, quick, and similar adjectives.

  • with

    can name a tool or material, not usually the activity being judged.

  • skilled in

    a more formal adjective phrase with a similar meaning.

文法句型

good at + activity

bad at + activity

用法筆記

Used with adjectives of skill, speed, or weakness, especially good, bad, quick, slow, and better. Distinguish from sense 4: this sense names the activity itself, not the cause of a feeling.

常見錯誤

❌Leo is good in math.
✅Leo is good at math.
💡after 'good', 'bad', and similar adjectives, English normally uses 'at' before the subject or skill.

6. the @ sign in an email address, placed between the user name and the domain name

6.介系詞A1
釋義

小老鼠

電子郵件位址中的 @ 符號

the @ sign in an email address, placed between the user name and the domain name.

例句

The address ends with @school.tw, not with @gmail.com.

那個地址是以 @school.tw 結尾，不是 @gmail.com。

同義詞
  • at sign

    the standard English name for the symbol.

  • @ symbol

    a clear descriptive label, common in instructions.

  • at symbol

    another common way to name the character in speech or writing.

文法句型

name + @ + domain

用法筆記

This sense names the symbol itself. In ordinary sentences, 'at' is a preposition before a noun phrase, but here it refers to the written character inside an email address.

常見錯誤

❌My email is tina.gmail.com.
✅My email is [email protected].
💡an email address needs the @ symbol between the name and the domain.

7. used before a number to show an exact price, temperature, speed, or other measur

7.介系詞B2
釋義

以；維持在

表示價格、溫度、速度等數值

used before a number to show an exact price, temperature, speed, or other measured level.

例句

Tickets were selling at $25 each outside the school concert hall.

學校音樂會會場外，門票正以每張25美元販售。

at + price

The bus was traveling at 80 kilometers an hour near Tainan.

那班公車在台南附近以每小時80公里行駛。

at + speed

同義詞
  • for

    can replace 'at' with prices, but not usually with temperatures or speeds

  • at a rate of

    a fuller, more formal paraphrase for speeds and rates

文法句型

at + price

at + temperature

at + speed or rate

用法筆記

Usually comes directly before a figure that names a price, speed, temperature, or rate. Distinguish from sense 8, which is mainly for figures written in invoices, lists, and other records.

常見錯誤

❌The bus was traveling in 80 kilometers an hour.
✅The bus was traveling at 80 kilometers an hour.
💡use 'at' before a speed.
❌Keep the medicine on 8°C.
✅Keep the medicine at 8°C.
💡use 'at' before an exact temperature.

8. used in bills, price lists, and similar records to mark the amount charged for o

8.介系詞
釋義

單價為

帳目或清單中標示單價、費率

used in bills, price lists, and similar records to mark the amount charged for one item or one unit.

例句

The invoice lists twelve lamps at NT$450 each for the cafe.

發票上列出十二盞燈，單價為450元，供咖啡館使用。

list item + at + unit price

On the order sheet, paper cups were entered at NT$2 each.

訂購單上記著紙杯單價為2元。

recorded figure in a list

同義詞
  • listed at

    more explicit, often used when describing catalog or menu prices

  • priced at

    common when the record focuses on the amount charged

文法句型

item + at + amount each

item + at + rate per unit

用法筆記

Mostly appears in written records such as invoices, order sheets, and catalogs. Unlike sense 7, this sense links a listed item to its recorded unit price or rate.

常見錯誤

❌The invoice lists ten pens for NT$15 each.
✅The invoice lists ten pens at NT$15 each.
💡in records, 'at' commonly links the item to the unit price.
❌The bill entered taxi rides in NT$300 a trip.
✅The bill entered taxi rides at NT$300 a trip.
💡use 'at' before the recorded rate.

9. used before a noun to show the state someone or something is in, or an activity

9.介系詞
釋義

處於

表示某種狀態、情況或持續活動

used before a noun to show the state someone or something is in, or an activity that is continuing.

例句

After the ceasefire, the border towns were finally at peace again.

停火後，那些邊境城鎮終於再次處於和平狀態。

fixed phrase: at peace

By dawn, the rescue crew was already at work on the bridge.

天一亮，救援隊就已經在橋上忙著作業。

fixed phrase: at work

同義詞
  • in a state of

    a more formal paraphrase for condition phrases

  • engaged in

    fits the activity reading, especially with work or action

文法句型

at + state noun

at + activity noun

用法筆記

Common in fixed combinations such as 'at peace', 'at war', 'at risk', and 'at work'. Distinguish from sense 1: here the noun names a condition or activity, not simply a place.

常見錯誤

❌The country stayed in war for years.
✅The country stayed at war for years.
💡several state phrases use 'at', not 'in'.
❌The patient is in rest now.
✅The patient is at rest now.
💡'at rest' is the fixed expression.

at — 動詞

at — 名詞