F-01
One or Many
一个还是多个💡 概念 Concept
Singular means one thing; plural means more than one. In English, most nouns form the plural by adding -s. The words this / that / these / those must also match: one thing → this, that; many things → these, those.单数指一个，复数指多个。英语中大多数名词加 -s 变复数。this / that / these / those 也要搭配一致：一个用 this、that；多个用 these、those。
📐 规则 Rules
单数
one book, a car, an apple
一本书、一辆车、一个苹果
复数 +s
two books, three cars, four apples
两本书、三辆车、四个苹果
this / these
this book → these books
这本书 → 这些书
that / those
that car → those cars
那辆车 → 那些车
✏️ 例句 Examples
I have one apple and two bananas.
我有一个苹果和两根香蕉。
This pen is mine. These pens are yours.
这支笔是我的，这些笔是你的。
Look at those birds in the sky!
看天上那些鸟！
⚠️ 常见错误 Common Mistakes
❌ I have two dog. → Plural needs -s: I have two dogs.❌ 复数要加 s：I have two dogs.（我有两只狗。）
❌ This are my shoes. → One thing takes this + is: These are my shoes.❌ this 配 is：These are my shoes.（这些是我的鞋。）
F-02
Spelling Rules
复数拼写规则💡 概念 Concept
Nouns ending in -s, -ss, -sh, -ch, -x or -o add -es. Nouns ending in consonant + y change to -ies. Nouns ending in -f or -fe often change to -ves.以 -s、-ss、-sh、-ch、-x、-o 结尾的名词加 -es；辅音字母 + y 结尾要变 -ies；以 -f / -fe 结尾的常变 -ves。
📐 规则 Rules
加 -es
bus → buses; watch → watches; box → boxes; potato → potatoes
公共汽车→buses；手表→watches；盒子→boxes；土豆→potatoes
辅音 + y
city → cities; baby → babies（但 boy → boys，元音+y 只加 s）
城市→cities；婴儿→babies（但 boy→boys，元音+y 直接加 s）
f / fe → ves
knife → knives; leaf → leaves
刀→knives；树叶→leaves
注意例外
photo → photos; piano → pianos; roof → roofs
照片→photos；钢琴→pianos；屋顶→roofs
✏️ 例句 Examples
Three buses stop at this station.
三辆公交车停在这个站。
The babies are sleeping now.
宝宝们现在正在睡觉。
Please cut the apples with clean knives.
请用干净的刀切苹果。
⚠️ 常见错误 Common Mistakes
❌ two citys → two cities❌ city 变复数要去 y 加 ies：two cities（两座城市）。
❌ three watchs → three watches❌ watch 结尾是 ch，要加 es：three watches（三块手表）。
❌ two knifes → two knives❌ knife 的 f 变 v 再加 es：two knives（两把刀）。
F-03
Irregular Plurals
不规则复数💡 概念 Concept
Some plurals do not follow any rule. You simply have to remember them: man → men, child → children, foot → feet. A few nouns look the same in singular and plural: sheep, fish.有些复数没有任何规则，只能记住：man → men（男人）、child → children（孩子）、foot → feet（脚）。少数名词单复数同形：sheep（羊）、fish（鱼）。
📐 规则 Rules
元音变化
man → men; woman → women; foot → feet; tooth → teeth; mouse → mice
男人→men；女人→women；脚→feet；牙→teeth；老鼠→mice
加 -en
child → children; ox → oxen
孩子→children；公牛→oxen
单复同形
sheep → sheep; fish → fish; deer → deer
羊、鱼、鹿 单复数相同
person → people
one person, two people
一个人，两个人
✏️ 例句 Examples
Three men are waiting at the door.
三个男人在门口等着。
The children are playing with their toys.
孩子们正在玩玩具。
There are five sheep on the hill.
山丘上有五只羊。
⚠️ 常见错误 Common Mistakes
❌ two mans → two men❌ man 的复数是 men：two men（两个男人）。
❌ The mouses ran away. → The mice ran away.❌ mouse 的复数是 mice：The mice ran away.（老鼠跑掉了。）
❌ three sheeps → three sheep❌ sheep 单复数同形：three sheep（三只羊）。
F-04
Countable & Uncountable
可数与不可数💡 概念 Concept
Countable nouns can be counted: a book, two books, many books. Uncountable nouns cannot: water, rice, money, information, advice, homework. They take no a / an and no plural. Use a piece of, a glass of, a lot of to talk about amounts.可数名词可以数：一本书、两本书、许多书。不可数名词不能数：水、米饭、钱、信息、建议、作业。它们前面不加 a / an，也没有复数形式。表示数量可用 a piece of、a glass of、a lot of。
📐 规则 Rules
可数
a book / two books / many books; a banana / some bananas
一本书/两本书/许多书；一根香蕉/一些香蕉
不可数
water, rice, money, information, advice, homework, news
水、米饭、钱、信息、建议、作业、新闻
计量表达
a glass of water; a piece of advice / paper / information
一杯水；一条建议 / 一张纸 / 一条信息
单数动词
The news is good. Money makes things easier.
The news is good.（新闻很好。）主语是不可数名词时用单数动词。
✏️ 例句 Examples
I drink a glass of water every morning.
我每天早上喝一杯水。
She gave me two pieces of advice.
她给了我两条建议。
How much money do you need?
你需要多少钱？
⚠️ 常见错误 Common Mistakes
❌ an information → a piece of information (or: some information)❌ information 不可数，不能说 an information：应说 a piece of information 或 some information。
❌ I have many moneys. → I have a lot of money.❌ money 不可数，没有复数：I have a lot of money.（我有很多钱。）
❌ The news are good. → The news is good.❌ news 看似复数，其实作单数：The news is good.（新闻很好。）