一般现在时：he, she, it (A1)

用 he, she, it 的时候，动词要加 -s。

He / she / it

He works in an office.
She lives in Haffenville.
It rains a lot here.
Not "He work in an office." — say "He works in an office.". -s 就是用来告诉你主语是 he、she 还是 it。
试一试: He ___ in an office. (works / work / working) 答案: works — 用 he 的时候，动词要加 -s：He works. work 是跟 I、you、we 和 they 搭配的形式，而 working 永远不能单独跟在 he 后面。

动词以 s, x, ch 或 sh 结尾时，词尾要加 -es。另外还有两个直接记住就好：go → goes 和 do → does。

She watches movies.
He pushes the door.
She fixes the car.
He goes to work.
试一试: She ___ movies. (watches / watchs / watch) 答案: watches — 在 ch 后面，词尾是 -es，不是 -s：watches。watchs 想法对了，但词尾错了；watch 完全没有词尾，那是跟 I、you、we 和 they 搭配的形式。

看看这个规律：study → studies · try → tries · fly → flies。y 变成 ies。但如果 y 前面是 a, e, i, o, 或 u，就保留 y，直接加 -s 就行：play → plays。

She studies English.
He tries hard.
but: play → plays (an a before the y)
试一试: She ___ English every day. (studies / studys / study) 答案: studies — 很接近了，y 要变化：study → studies（不是 "studys"）。

用 he, she, it 的时候，说“不”要用 doesn't。变化都放在 doesn't 上了，所以后面的动词保持原形。

He doesn't work here.
She doesn't live in Haffenville.
It doesn't cost ten dollars.
Not "She doesn't lives here." — say "She doesn't live here.". doesn't 已经告诉你主语是 she 了，所以后面接动词原形。
试一试: Hiroshi ___ a jacket. It is very hot. (doesn't wear / doesn't wears / don't wear) 答案: doesn't wear — Hiroshi 是 he，所以否定要用 doesn't 加动词原形：doesn't wear。doesn't wears 在动词上又加了词尾，don't wear 是 I、you、we、they 用的形式。

问 he, she, it 做什么动作时，先用 Does 开头，接着说人，再接动词原形。

Does he work here?
Does she live in Haffenville?
Does it cost ten dollars?
Not "Does he works here?" — say "Does he work here?". Does 已经告诉你主语是 he 了，所以后面接动词原形。
试一试: ___ Camila buy her clothes at Mosh Market? (Does / Do / Is) 答案: Does — Camila 是 she，所以问句用 Does 开头。Do 是 I、you、we、they 用的；Is 开头的问句问的是描述的词或东西，不是动作。

用 Does 开头的问题，回答时也会带回 does 或 doesn't。你在 Yes, I do. 里已经见过：问句开头的那个词，就是回答结尾的那个词。

Does she cook dinner? - Yes, she does.
Does he study at home? - No, he doesn't.
Does it open at nine? - Yes, it does.
Not "Does she cook dinner? - Yes, she cooks." — say "Does she cook dinner? - Yes, she does.". 简短回答保留 does，所以不用再把动词说一遍。
试一试: Amina: Does Hiroshi walk to Mosh Market? Sofia: ___ His house is next to it. (Yes, he does. / Yes, he do. / Yes, he is.) 答案: Yes, he does. — 问题用 Does 开头，所以回答要带回 does。do 是 I、you、we、they 用的形式，is 回答的是用 Is 开头的问题。

你已经会说 She has a bike. 了。要说“不”或者提问时，由 doesn't 和 Does 来负责变化，has 就变回原形 have。

She has a bike.
She doesn't have a bike.
Does she have a bike?
Not "She doesn't has a bike." — say "She doesn't have a bike.". doesn't 已经告诉你主语是 she 了，所以后面接原形 have。
试一试: Ira: Does Liam's apartment have three bedrooms? Amina: No, it ___ three. It has two. (doesn't have / doesn't has / don't have) 答案: doesn't have — apartment 是 it，所以否定要用 doesn't 加原形 have。doesn't has 在动词上还留着词尾，don't have 是 I、you、we、they 用的形式。
试一试: Wei: ___ Matilda have a big kitchen in her house? Lani: Yes, she does. She cooks dinner for her friends there. (Does / Has / Is) 答案: Does — Matilda 是 she，所以问句用 Does 开头，后面的 have 保持原形。Has 是把词尾放到了句首，而不是用 Does；Is 开头的问句问的是一个人是什么样的，不是问他有什么。

每个动词前先问一句：主语是谁？ he/she/it → 加 -s。I/you/we/they → 不加词尾。

He plays. / They play.
She works. / We work.
Not "He play. / They plays." — say "He plays. / They play.". 动词一样，是主语决定要不要加词尾。
试一试: My sister ___ tea, but my parents ___ coffee. (drinks … drink / drink … drinks / drinks … drinks) 答案: drinks … drink — My sister = she → drinks（加 -s）。My parents = they → drink（不加词尾）。
试一试: My brother ___ in a bank, but his friends ___ in a shop. (works … work / work … works / works … works) 答案: works … work — My brother = he → works（加 -s）。His friends = they → work（不加词尾）。每一个都由“谁在做”来决定。