English Grammar · A2 · ⁨英语语法 · A2⁩

The present simple tense is used to talk about things that happen regularly and facts that are always true: daily habits, schedules, scientific facts.

Structure: 主语 + 动词原形

我I 喝drink 咖啡coffee 每every 早上morning.

I drink coffee every morning.

我们We 住live 在in 上海Shanghai.

We live in Shanghai.

Scientific facts also use the present simple:

水Water 沸腾boils 在at 一one 百hundred 度degrees.

Water boils at one hundred degrees Celsius.

It is often used with adverbs of frequency: always, usually, often, sometimes, never.

她She 总是always 乘坐takes （冠词）the 公交车bus.

She always takes the bus.

Note

• When talking about current habits, do not add a be verb: ~~I am drink coffee~~ ✗ → I drink coffee ✓.
• Adverbs of frequency usually go before the main verb, but after the be verb: She is often late.

When the subject is he / she / it (third person singular), the verb takes -s or -es.

Structure: He / She / It + 动词 + -s

他He 工作works 在in 一家a 银行bank.

He works at a bank.

我的My 姐姐sister 喜欢likes 音乐music.

My sister likes music.

Spelling rules:

• Generally add -s directly: work → works, play → plays.
• Ends in -s / -sh / -ch / -x / -o, add -es: watch → watches, go → goes.
• Consonant letter + -y ending, change y to i and add -es: study → studies, fly → flies.

她She 看watches 电视TV 在at 晚上night.

She watches TV at night.

Note

• Only he / she / it takes -s; I / you / we / they do not take it: ~~They likes~~ ✗ → They like ✓.
• have is special: he / she / it uses has (not ~~haves~~).

For negative and interrogative forms in the Present Simple, use the auxiliary verb do / does. Use does for he / she / it, and do for other subjects.

Negative structure: 主语 + don't / doesn't + 动词原形

我I 不don't 吃eat 肉meat.

I don't eat meat.

他He 不doesn't 喜欢like 咖啡coffee.

He doesn't like coffee.

Interrogative structure: Do / Does + 主语 + 动词原形 ?

（助动词）Do 你you 说speak 英语English?

Do you speak English?

（助动词）Does 她she 工作work 这里here?

Does she work here?

Short answers: Yes, I do. / No, he doesn't.

Note

• After using do / does, the verb returns to its base form (no longer adds -s): ~~He doesn't likes~~ ✗ → He doesn't like ✓.
• Don't forget the auxiliary verb: in formal contexts say Do you…?, not just ~~You speak English?~~.

Common Errors

• ❌ ~~She don't like it.~~ → ✓ She doesn't like it. — For third-person singular negatives, use doesn't, not don't.
• ❌ ~~Does he has a car?~~ → ✓ Does he have a car? — When using does, even has reverts to the base form have.
• ❌ ~~Everyone know the answer.~~ → ✓ Everyone knows the answer. — everyone / everybody / nobody are treated as singular, so add -s to the verb.
• ❌ ~~I am usually going to school by bike.~~ → ✓ I usually go to school by bike. — Repeated habits use the Present Simple, not the continuous tense.

The Present Continuous tense describes actions that are happening right now.

Structure: 主语 + am / is / are + 动词-ing(I → am; he / she / it → is; you / we / they → are)

我I 正在am 读reading 一本a 书book.

I am reading a book.

他们They 正在are 踢playing 足球football.

They are playing football.

Spelling of -ing:

• Generally add -ing directly: read → reading.
• End in silent -e, drop e and add -ing: make → making, write → writing.
• Stressed closed syllable (consonant + vowel + consonant), double the final consonant: run → running, sit → sitting.

她She 正在is 写writing 一封an 电子邮件email.

She is writing an email.

Note

• Don't forget the be verb: ~~I reading~~ ✗ → I am reading ✓.
• State verbs (like, know, want, have = possess) generally do not use the continuous tense: ~~I am knowing~~ ✗ → I know ✓.

Both tenses relate to "now," but their meanings differ:

• Present Simple: Habits or repeated actions.
• Present Continuous: Actions happening at this very moment.

他He 通常usually 步行walks 去to 上班work.

He usually walks to work. (Habit → Present Simple)

今天Today 他he 正在is 乘坐taking （冠词）the 公交车bus.

He is taking the bus today. (Right now → Present Continuous)

Time expressions help distinguish them:

• Present Simple: every day, usually, often, always.
• Present Continuous: now, right now, at the moment, today.

Note

• Temporary situations use the continuous tense: She is living with her aunt this month. (She is temporarily staying with her aunt this month.)
• Long-term facts use the Present Simple: She lives in Beijing. (She lives in Beijing.)

Common Errors

• ❌ ~~They are play football now.~~ → ✓ They are playing football now. — With be, the verb must also take -ing; both elements are required.
• ❌ ~~She is cooking every day.~~ → ✓ She cooks every day. — every day signals a habit, so use the Present Simple.
• ❌ ~~Where is Tom? — He plays football.~~ → ✓ He is playing football. — To answer "what is he doing right now?", use the continuous tense.
• ❌ ~~He is writeing a letter.~~ → ✓ He is writing a letter. — Verbs ending in a silent -e drop the e before adding -ing.

The Past Simple tense describes actions or states that were completed in the past. Regular verbs add -ed to the end.

Structure: 主语 + 动词-ed(same for all persons)

我I 看watched 一部a 电影film 昨天yesterday.

I watched a movie yesterday.

我们We 打played 篮球basketball 上last 周week.

We played basketball last week.

Spelling of -ed:

• Generally add -ed directly: work → worked, play → played.
• End in -e, only add -d: like → liked, live → lived.
• Consonant + -y ending, change y to i and add -ed: study → studied, try → tried.
• Stressed closed syllable, double the final consonant: stop → stopped, plan → planned.

Note

• The past tense form does not change based on person: I worked, she worked (no -s).
• Often used with past time markers: yesterday, last week, in 2019, two days ago.

Many common verbs are irregular; their past forms must be memorized individually without adding -ed.

我I 去went （介词）to 北京Beijing 上last 月month.

I went to Beijing last month.

她She 看见saw 她的her 朋友friends.

She met her friend.

High-frequency irregular verbs you must memorize:

• go → went, have → had, do → did, make → made.
• see → saw, come → came, get → got, take → took.
• eat → ate, buy → bought, think → thought, say → said.

我们We （吃了）had 一顿a 丰盛的big 晚餐dinner.

We had a big dinner.

Note these follow no pattern; practice reading and memorizing them frequently.

For negative and interrogative forms in the Past Simple, use the auxiliary did (past form). The following verb returns to its base form.

Negative structure: 主语 + didn't + 动词原形

我I 没有didn't 去go （介词）to 上学school.

I didn't go to school.

Interrogative structure: Did + 主语 + 动词原形 ?

（助动词）Did 你you 看见see （冠词）the 电影film?

Did you see that movie?

Short answers: Yes, I did. / No, I didn't.

Note

• After using did / didn't, the verb must be in the base form: ~~I didn't went~~ ✗ → I didn't go ✓.
• The past tense of the be verb (was / were) does not use did: Were you tired? (Were you tired?)

Common Errors

• ❌ ~~I go to Beijing last month.~~ → ✓ I went to Beijing last month. — Chinese verbs do not change form, but in English, once a past time marker is present, you must switch to the past tense. This is the most common error.
• ❌ ~~She buyed a new phone.~~ → ✓ She bought a new phone. — Irregular verbs cannot simply add -ed.
• ❌ ~~I didn't was hungry.~~ → ✓ I wasn't hungry. — For negative sentences with the verb 'be', use wasn't / weren't directly, not didn't.
• ❌ ~~yesterday night~~ → ✓ last night — Fixed expression: 'last night' is used for last evening, not 'yesterday night' (though 'yesterday morning/afternoon' is correct).

The past continuous tense describes an action in progress at a specific moment in the past.

Structure: 主语 + was / were + 动词-ing(I / he / she / it → was; you / we / they → were)

在At 八点eight 我I （过去进行）was 做饭cooking.

I was cooking at eight o'clock.

他们They （过去进行）were 看watching 电视TV.

They were watching TV at that time.

Note

• Don't mix up was and were: Use was for I / he / she / it; use were for you / we / they.
• Negative: wasn't / weren't + V-ing. Question: Was / Were + subject + V-ing?

The past continuous is often used with the simple past to describe "an ongoing action interrupted by another event".

• while + past continuous (the longer background action).
• when + simple past (the sudden, short action).

当...时While 我I （过去进行）was 睡觉sleeping （冠词）, the 电话phone 响了rang.

The phone rang while I was sleeping.

她She （过去进行）was 做饭cooking 当...时when 我I 到达arrived.

When I arrived, she was cooking.

Compare the two tenses:

• The ongoing background action → Past continuous (was cooking).
• The short action that interrupts it → Simple past (arrived).

Note

• Two long actions happening simultaneously both use the past continuous: While I was reading, she was writing (I was reading, and she was writing).
• 'when' can also be followed by the past continuous, but the meaning changes. Beginners should first memorize the common collocations mentioned above.

Common Errors

• ❌ ~~I was watch TV when he called.~~ → ✓ I was watching TV when he called. — After was / were, you must use the -ing form.
• ❌ ~~They was playing games.~~ → ✓ They were playing games. — Use were for you / we / they.
• ❌ ~~When I was arriving, she was cooking.~~ → ✓ When I arrived, she was cooking. — Arriving is a brief, instantaneous action, so use the simple past; only the longer background action uses the continuous form.
• ❌ ~~I was knowing the answer.~~ → ✓ I knew the answer. — Stative verbs (know, like, want) are also generally not used in the continuous form in the past tense.

The present perfect tense connects the past and the present: a past action has an effect on the present now, or it refers to life experience.

Structure: 主语 + have / has + 过去分词(he / she / it → has)

我I （完成时）have 完成finished 我的my 作业homework.

I have finished my homework. (So I am free now)

她She （完成时）has 丢失lost 她的her 钥匙keys.

She has lost her keys. (She hasn't found them yet)

Past Participle:

• Regular verbs = -ed: work → worked, finish → finished.
• Irregular verbs must be memorized: go → gone, see → seen, do → done, be → been, eat → eaten.

Note: Present perfect usually does not specify exact times. If you mention a specific past time (yesterday, in 2019), use the simple past instead.

These words are frequently used with the present perfect tense:

• ever: Used in questions to mean "at any time." never: "not ever."
• just: "just now." already: "already." yet: Used at the end of negative or interrogative sentences to mean "not yet."

（完成时）Have 你you 曾经ever 去过been （介词）to 伦敦London?

Have you ever been to London?

我I （完成时）have 刚刚just 吃过eaten 午饭lunch.

I have just had lunch.

他He 还没hasn't 完成finished （句末"还没"）yet.

He hasn't finished yet.

To say how long something has "continued," use for or since:

• for + a period of time: for three years, for a week.
• since + starting point: since 2020 (from the year 2020), since Monday (from Monday).

我I （完成时）have 住lived 这里here （持续）for 五five 年years.

I have lived here for five years. (And I still live here)

我们We （完成时）have 认识known 彼此each other 自从since 2018年2018.

We have known each other since 2018.

Note: Use 'for' with duration and 'since' with a starting point; don't mix them up: ~~for 2018~~ ✗ → since 2018 ✓.

Common Errors

• ❌ ~~I have seen him yesterday.~~ → ✓ I saw him yesterday. — Once a specific past time is mentioned (yesterday, last week, in 2019), switch to the simple past.
• ❌ ~~I live here for ten years.~~ → ✓ I have lived here for ten years. — "Lived here for ten years and still live here" requires the present perfect. Chinese lacks this distinction, making it easy to overlook.
• ❌ ~~She has go home.~~ → ✓ She has gone home. — After have / has, use the past participle, not the base form.
• ❌ ~~Have you ever went to Beijing?~~ → ✓ Have you ever been to Beijing? — Use have been to for "visited a place."
• Distinguish gone and been: He has gone to Beijing. (He went there and hasn't returned yet) vs He has been to Beijing. (He visited there and has come back).

will is used to talk about the future, especially spontaneous decisions, predictions, and promises.

Structure: 主语 + will + 动词原形(Same for all persons; will not = won't)

我I 将will 打电话call （给你）you 今晚tonight.

I will call you tonight.

（天气it）It 将will 下雨rain 明天tomorrow.

It will rain tomorrow.

Note

• Use the base form of the verb after will: ~~will to go~~ ✗ → will go ✓.
• Negative uses won't: I won't be late. (I will not be late.)

be going to is used to talk about plans and predictions based on current evidence.

Structure: 主语 + am / is / are + going to + 动词原形

我们We （be）are 打算going to 拜访visit 我们的our 奶奶grandma.

We are going to visit Grandma. (A plan already made)

看Look （介词）at （冠词）the 云clouds （天气it）! It （be）is 将要going to 下雨rain.

Look at those clouds! It's going to rain. (Based on current signs)

will or going to?

• Spontaneous decision → will: The phone is ringing. I'll get it. (Phone rings, I decide now to answer.)
• Pre-planned intention → going to: I'm going to study tonight. (I have planned to study tonight.)

The present continuous can also express scheduled future events (especially when there is a definite time or place).

Structure: 主语 + am / is / are + 动词-ing + 将来时间

我I （be）am 见面meeting 汤姆Tom 明天tomorrow.

I am meeting Tom tomorrow. (An appointment has been set)

我们We （be）are 飞flying 去to 东京Tokyo 在on 周五Friday.

We are flying to Tokyo on Friday. (Tickets are booked)

Note: This usage emphasizes that something is "already arranged," which is similar to 'be going to'; the key factor is having a definite future time.

Common Errors

• ❌ ~~I go to Shanghai tomorrow.~~ → ✓ I am going to Shanghai tomorrow. / I will go… — The Chinese "I go to Shanghai tomorrow" lacks a future marker; English requires adding (will / going to / present continuous).
• ❌ ~~We will going to visit grandma.~~ → ✓ We are going to visit… / We will visit… — will and be going to are separate structures and cannot be combined.
• ❌ ~~She will comes tomorrow.~~ → ✓ She will come tomorrow. — After will, use the base form of the verb; no -s is added for any person.
• Exception: Timetables (trains, flights, classes) can use the simple present to express the future: The train leaves at 9. (The train leaves at nine o'clock.)

Comparatives are used to compare two things, often used with than (compared to).

Short adjectives + -er; long adjectives use more + adjective.

我的My 包bag 是is 更大bigger 比than 你的yours.

My bag is bigger than yours.

这This 书book 是is 更more 有趣interesting 比than 那本that one.

This book is more interesting than that one.

Formation Rules:

• Monosyllabic: add -er → tall → taller, fast → faster.
• Ending in consonant + y: change y to i and add -er → happy → happier, easy → easier.
• Two or more syllables: use more → expensive → more expensive.
• Irregular: good → better, bad → worse, far → further.

Note: Avoid "double comparison": ~~more bigger~~ ✗ → bigger ✓.

Superlatives indicate "the most …" (three or more), preceded by the.

Short adjectives + -est; long adjectives use the most + adjective.

他He 是is （冠词）the 最高tallest 在in （冠词）the 班级class.

He is the tallest in the class.

这This 是is （冠词）the 最most 贵expensive 手机phone.

This is the most expensive phone.

Formation Rules:

• Monosyllabic: the + -est → fast → the fastest.
• Long adjectives: the most → the most beautiful.
• Irregular: good → the best, bad → the worst.

Note: Do not forget the before superlatives: ~~he is tallest~~ → he is the tallest.

as + adjective + as means "as … as …".

她She 是is 和as 高tall 一样as 她her 妈妈mother.

She is as tall as her mother.

Negative not as ... as means "not as … as …":

今天Today （是）is 不not 像as 热hot 一样as 昨天yesterday.

It is not as hot today as yesterday.

Note: Place the base form of the adjective (not the comparative) in the middle: ~~as taller as~~ ✗ → as tall as ✓.

Common Errors

• ❌ ~~It is more cheap.~~ → ✓ It is cheaper. — Use -er for monosyllabic adjectives, not more.
• ❌ ~~He is taller than me a lot.~~ → ✓ He is much taller than me. — "A lot" translates to much, which goes before the comparative.
• ❌ ~~My bag is bigger than your.~~ → ✓ …bigger than yours. — Use yours / mine / hers (nominal possessive pronouns) after than.
• ❌ ~~Beijing is bigger than any city in China.~~ → ✓ …than any other city in China. — Do not forget other, otherwise it implies comparing itself to itself.

a and an are indefinite articles, used before singular countable nouns to mean "one (non-specific)".

• a is used before consonant sounds: a book, a car, a university (pronounced /j/ sound).
• an is used before vowel sounds: an apple, an hour (h is silent).

我I 有have 一个a 问题question.

I have a question.

她She 是is 一名an 工程师engineer.

She is an engineer.

Note: Look at the pronunciation, not the letter: an hour (h is silent → an), a university (pronounced /j/ → a).

the is the definite article, indicating specificity — both speaker and listener know exactly which one.

请Please 关close （这扇）the 门door.

Please close (this) door.

Common uses of the:

• When mentioned previously or referred to again: I saw a cat. The cat was black. (I saw a cat. That cat was black.)
• For unique things in the world: the sun, the moon.
• Before superlatives: the best, the tallest.

（那个）The 太阳sun 是is 非常very 明亮bright 今天today.

The sun is very bright today.

Sometimes no article (zero article) is placed before a noun:

• Plural / uncountable nouns expressing generalization: I like music. (I like music.) Cats are cute. (Cats are cute.)
• Proper nouns: names, most countries, cities: China, Tom, Beijing.
• Some fixed phrases: go to school / bed / work (indicating purpose, without the).

我I 去go （介词）to 上学school 乘by 自行车bike.

I go to school by bike.

水Water 是is 重要important.

Water is important.

Note: Do not use the when plural / uncountable nouns express generalization: ~~I like the music~~ (general sense) ✗ → I like music ✓.

Common Errors

• ❌ ~~I want to be teacher.~~ → ✓ I want to be a teacher. — Add a / an before professions; direct translation of Chinese "to be a teacher" often omits this.
• ❌ ~~I went to home.~~ → ✓ I went home. — home is used as an adverb here: go home, get home; do not use to or the before it.
• ❌ ~~He plays the football.~~ → ✓ He plays football. — No the before sports; but add the for instruments: play the piano / violin.
• Distinguish: go to school (attend school, purpose) vs go to the school (go to the school building, e.g., parents attending a meeting). Same logic applies to bed / hospital / work.

English nouns are divided into two categories:

• Countable nouns: can be counted, have singular and plural forms. a book → two books.
• Uncountable nouns: cannot be directly counted, have no plural form. water, music, money, information.

我I 买了bought 三three 苹果apples.

I bought three apples. (Countable)

我I 需要need 一些some 水water.

I need some water. (Uncountable, no ~~waters~~)

Note

• Uncountable nouns take a singular verb: The news is good. (The news is good.)
• To count uncountable nouns, use measure words: a glass of water, a piece of information.

some and any mean "some", used before plurals or uncountable nouns:

• some: used in affirmative sentences (also used in polite requests / invitations).
• any: used in negative sentences and interrogative sentences.

（有）There 有are 一些some 鸡蛋eggs 在in （冠词）the 冰箱里fridge.

There are some eggs in the fridge.

（有）There 没有isn't 任何any 牛奶milk.

There is no milk left.

（助动词）Do 你you 有have 任何any 问题questions?

Do you have any questions?

Note: When offering drinks to others, some is commonly used to sound polite: Would you like some tea?

Used to express "a lot":

• many + countable plural: many books.
• much + uncountable: much water (mostly used in negative sentences / questions).
• a lot of + both types (most common in positive sentences).

（有）There 有are 许多many 人people 这里here.

There are many people here.

我们We 没有don't 有have 多少much 时间time.

We don't have much time left.

她She 有has 许多a lot of 朋友friends.

She has a lot of friends.

Note: In positive sentences, much is rarely used; instead use a lot of: ~~I have much money~~ → I have a lot of money.

Common Errors

• ❌ ~~informations / advices / homeworks / furnitures~~ → ✓ information / advice / homework / furniture — These words are uncountable in English (although Chinese can say "several pieces of advice" or "pieces of furniture"). They never take a plural form.
• ❌ ~~a bread / a paper~~ → ✓ a piece of bread / a piece of paper — Uncountable nouns require measure words to be counted.
• ❌ ~~How much apples do you want?~~ → ✓ How many apples…? — Use many for countable plurals and much only for uncountable nouns.
• ❌ ~~There aren't some eggs.~~ → ✓ There aren't any eggs — Replace some with any in negative sentences.

can expresses ability or possibility; could is the past tense of can, and is also used for more polite requests. All modal verbs are followed by the base form of the verb.

我I 会can 游泳swim.

I can swim.

她She 会could 读read 在at 四岁four.

She could read at the age of four. (Past ability)

能Could 你you 帮help 我me 请, please?

Could you please help me? (Polite request)

Note

• After a modal verb, use the base form: ~~can to swim~~ ✗ → can swim ✓.
• Negative: cannot / can't, could not / couldn't.

should expresses advice or "should".

你You 应该should 看see 一位a 医生doctor.

You should see a doctor.

我们We 不应该shouldn't 浪费waste 水water.

We shouldn't waste water.

Note: should gives advice and is less forceful than must; it is also followed by the base form of the verb.

Both express "must":

• must: Often indicates something the speaker considers important, or a rule.
• have to: Often indicates an external requirement (regulation, objective necessity).

你You 必须must 系wear （冠词）a 安全带seatbelt.

You must wear a seatbelt.

我I 不得不have to 起床get up 早early.

I have to get up early.

Note

• mustn't = "prohibited": You mustn't smoke here. (Smoking is prohibited here.)
• don't have to = "not necessary": You don't have to come. (You don't need to come.)
• Note that their meanings are completely different: one means "forbidden," the other means "not necessary."

Common Errors

• ❌ ~~You must to wear a helmet.~~ → ✓ You must wear a helmet — All modal verbs (can / could / should / must) are followed directly by the base form and never take to.
• ❌ ~~She musts study harder.~~ → ✓ She must study harder — Modal verbs do not take a third-person singular -s.
• ❌ Wanting to say "you don't need to come" but saying ~~You mustn't come.~~ → ✓ You don't have to come — mustn't means "forbidden," while don't have to means "not necessary." Their meanings are exactly opposite.
• ❌ ~~Yesterday I must work late.~~ → ✓ Yesterday I had to work late — must has no past tense; use had to for past obligations.

When indicating time, at / in / on each have specific uses:

• at + specific time / point: at 7 o'clock, at night, at the weekend.
• on + specific day / date: on Monday, on May 1st, on my birthday.
• in + longer period: in the morning, in July, in 2020, in winter.

（冠词）The 课class 开始starts 在at 九点nine.

This class starts at nine o'clock.

我们We 见面met 在on 周五Friday.

We met on Friday.

我的My 生日birthday 在is 在in 五月May.

My birthday is in May.

Note: The scope increases from small to large: at (point) → on (day) → in (month / year / period).

When indicating location:

• at + a specific point / place: at the bus stop, at home, at school.
• in + interior space: in the room, in China, in a box.
• on + surface / line: on the table, on the wall, on the second floor.

她She 在is （在）at 家home.

She is at home.

（冠词）The 书book 在is 在on （冠词）the 桌子上table.

The book is on the table.

（有）There 有are 鱼fish 在in （冠词）the 河里river.

There are fish in the river.

Indicating direction / movement:

• to: Towards a place. into: Entering inside. out of: Coming out from inside.
• up (upward) / down (downward) / across (cross over) / through (pass through the interior).

我I 去go 去to 上班work 乘by 公交车bus.

I go to work by bus.

（冠词）The 猫cat 跳jumped 进入into （冠词）the 箱子box.

The cat jumped into the box.

Note: to indicates "going somewhere," so do not confuse it with at (being somewhere): go to school (go to school) vs be at school (be at school).

Common Errors

• ❌ ~~in Monday~~ → ✓ on Monday; ❌ ~~at July~~ → ✓ in July — Use on for specific days and in for months / years.
• ❌ ~~in the morning of Monday~~ → ✓ on Monday morning — When referring to the morning / evening of a specific day, the preposition upgrades to on.
• ❌ ~~I arrived to Beijing.~~ → ✓ I arrived in Beijing. / I arrived at the station — arrive does not take to; use in for large places and at for small locations.
• ❌ ~~listen music / look the picture / wait him~~ → ✓ listen to music / look at the picture / wait for him — Although these verbs may not take prepositions in Chinese, the corresponding prepositions in English cannot be omitted.

Conjunctions link two ideas together:

• and (and): Parallel, additive. but (but): Contrast, opposite.
• or (or): Choice. so (so): Result. because (because): Reason.

我I （过去）was 累tired 所以, so 我I 去went （介词）to 睡觉bed.

I was tired, so I went to bed.

她She 留在stayed 家home 因为because （天气it）it （过去）was 下雨raining.

She stayed at home because it was raining.

Note: so introduces a result, while because introduces a reason; do not mix them up: Tired → so go to sleep; Slept → because tired.

Conditional sentences express "if... then...":

• Zero Conditional (universal facts): If + 一般现在时, 一般现在时.
• First Conditional (future possibilities): If + 一般现在时, will + 动词原形.

如果If 你you 加热heat 冰ice （它）, it 融化melts.

If you heat ice, it melts. (Universal fact → Zero Conditional)

如果If （天气it）it 下雨rains 我们, we 将will 留stay 家home.

If it rains, we will stay at home. (Future possibility → First Conditional)

Note: In clauses introduced by if, use the present simple even when referring to the future: ~~If it will rain~~ ✗ → If it rains ✓.

Adverbs of frequency indicate "how often": always (100%) > usually > often > sometimes > rarely > never (0%).

Position Rules:

• Place them before the main verb.
• But place them after the be verb.

我I 总是always 刷brush 我的my 牙teeth.

I always brush my teeth. (Before a lexical verb)

他He （be）is 从不never 迟到late.

He is never late. (After a be verb)

Note: Adverbs of frequency go before lexical verbs and after be verbs: I often read; She is often busy.

Common Errors

• ❌ ~~Because it was raining, so we stayed home.~~ → ✓ Because it was raining, we stayed home. / It was raining, so we stayed home. — In Chinese, "because... so..." appears as a pair, but in English, you can only keep one of because or so.
• ❌ ~~Although he is rich, but he is not happy.~~ → ✓ Although he is rich, he is not happy. — Similarly, in the Chinese structure "although... but...", you can only choose one of although or but.
• ❌ ~~I like apples and I like bananas and I like oranges.~~ → ✓ I like apples, bananas and oranges. — When listing multiple items, separate them with commas and use and only before the final item.
• ❌ ~~I play sometimes football.~~ → ✓ I sometimes play football. / I play football sometimes. — An adverb cannot be placed between a verb and its object.