單數與複數

由兩個對稱部分組成的東西，即使只有一件，也用複數名詞和複數動詞：trousers, jeans, shorts, pyjamas, glasses, sunglasses, scissors, headphones。要數它們，就用 a pair of / two pairs of。

• These jeans are too tight.

  這條牛仔褲太緊了。（不說：is）

• Where are my glasses? I can't find them.

  我的眼鏡在哪兒？我找不到了。

• I bought a pair of shorts and two pairs of socks.

  我買了一條短褲和兩雙襪子。

• This pair of scissors is really sharp.

  這把剪刀非常鋒利。（主語是 pair → 用 is）

💡中文說“一條褲子”“一副眼鏡”，把它們當成一件東西，所以學習者常寫出 a jeans 或 my glasses is。在英語裡，這些詞沒有單數形式——要用 a pair of 或 some：I need some new glasses / a new pair of glasses.

• news 是不可數名詞：The news is good. 一條訊息說 a piece of news（不說：a news）。
• 以 -ics 結尾的學科和領域：maths (AmE: math), physics, economics, politics, athletics, gymnastics → 動詞用單數：Physics is hard.（politics 表示“某人的政治觀點”時，可以用複數。）
• means, series, species 單複數同形：a TV series → two TV series；a means of transport → many means of transport。

• The news is on at seven.

  新聞七點播出。

• I have some good news for you.

  我有個好訊息要告訴你。（不說：a good news）

• Economics is my favourite subject.

  經濟學是我最喜歡的科目。

• This drama series is very popular in Vietnam.

  這部電視劇在越南很受歡迎。

family, team, staff, government, company, class, audience, committee 指的是一群人。在英式英語中，動詞可以用單數（把整個群體看作一個整體），也可以用複數（看作其中的各個成員）。美式英語通常用單數。

police 和 people 總是用複數動詞。指一個人時說 a police officer、a person（不說：a police）。person 的常用複數是 people；persons 只出現在正式文本中（告示、法律）。

• The team is / are training hard for the final.

  球隊正在為決賽刻苦訓練。（英式：兩種都可以；美式：用 is）

• The police are looking for the driver.

  警察正在尋找那名司機。（不說：is）

• Her brother is a police officer.

  她哥哥是一名警察。

• There were a lot of people at the market.

  市場上有很多人。

💡一旦選定了單數或複數，整句話就要保持一致：The team is happy with its result / The team are happy with their result.

把一筆錢、一段時間或一段距離看作一個總量時，即使名詞帶 -s，動詞也用單數。

• Two hundred dollars is a lot for a pair of shoes.

  一雙鞋兩百美元可不便宜。（不說：are）

• Three years is a long time to wait.

  等三年可是很長的時間。

• Five kilometres isn't far. Let's walk.

  五公里不遠，我們走路去吧。

但如果想的是一個個單位逐一過去，用複數動詞依然很自然：Ten years have passed since we left school.

• ✗My new jeans is too long.

  ✓My new jeans are too long.

  jeans 是複數名詞。

• ✗I need a new trouser.

  ✓I need new trousers / a new pair of trousers.

  沒有單數形式；用 a pair of。

• ✗The news are very bad today.

  ✓The news is very bad today.

  news 是不可數名詞。

• ✗The police is coming.

  ✓The police are coming.

  police 總是用複數動詞。

• ✗There were many persons at the party.

  ✓There were many people at the party.

  person 的常用複數是 people。

• ✗Physics are difficult.

  ✓Physics is difficult.

  以 -ics 結尾的學科 → 用單數。