Odie的英语课

上节课讲的是“不必（做某事）”，用 don't/doesn't have to，needn't (need not)，don't/doesn't need to，这节课我们讲 

mustn't (must not)
不能……

You mustn't play here – it's dangerous!
你不能在这里玩，这很危险！

He mustn't eat peanuts. He's allergic to nuts.
他不能吃花生。他对坚果过敏。
peanut(s) 花生（pea 豌豆 + nut坚果）
allergic 过敏的
be allergic to 对……过敏

You must not park outside the entrance.
你不能把车停在入口外。
park 动词，停（车）
entrance 入口

You must not make noise after 9 o'clock.
9点钟以后你不能吵闹。

不允许做某事也可以用 can't：
You can't go out tonight. You've got homework.
你今晚不能出去，你有作业要做。

前面讲的是 obligation，必须要做某事时，用 must, have (got) to, need to；

如果要讲某事不是 obligation，不是必要做的，可以用：

don't / doesn't have to 

needn't (need not)

don't / doesn't need to

不必……

我晚上不必工作。

I don't have to work in the evening.

I needn't work in the evening.

I don't need to work in the evening.

她晚上不必工作。

She doesn't have to work in the evening.

She needn't work in the evening.

She doesn't need to work in the evening.

旅行中你不必带食物。

You don't have to bring food on the trip.

You needn't bring food on the trip.

You don't need to bring food on the trip.

别担心。Don't worry (about it).

—> 你不必担心。

You needn't worry about it.

You don't have to worry about it.

You don't need to worry about it.

+ 我会处理好的。

take care of something 处理，负责

I'll take care of it.

—> 你不必担心。我会处理好的。

You needn't worry about it. I'll take care of it.

You don't have to worry about it. I'll take care of it.

You don't need to worry about it. I'll take care of it.

填空

① I ___ buy some new clothes. Mine look so old. 

② I ___ buy some new clothes. I'm starting a new job as a teacher and we have to wear formal clothes.

I must buy some new clothes. Mine look so old. 
我必须买一些新衣服。我的衣服看起来太旧了。
I've got to / I have to buy some new clothes. I'm starting a new job as a teacher and we have to wear formal clothes.
我得买些新衣服。我要开始一份教师的新工作，我们必须穿正装。
formal clothes 正装，正式的服装
formal 正式的，正规的，适合正式场合的

need to
必须，需要

I need to go to the toilet.
我（需）要去一下洗手间。

She needs to go to the doctor. She gets headaches every day.
她需要去看医生。她每天都头疼。
headache(s) 头痛

Need to 变疑问句需要使用助动词 do 或 does：
Do you need to pass an exam to get into university?
你需要通过考试才能进入大学吗？

Does she need to get a job?
她需要找工作吗？

Have got to 只用于现在时态，have to 可以用于现在时、将来时、过去时。

我必须得复习考试。

I've got to study for the exam. [现在时]

X 不说 I'll have got to study for the exam. 或 I had got to.... X

I have to study for the exam. [现在时]

I'll have to study for the exam. [将来时]

I had to study for the exam. [过去时]

将来时态，当将来必须要做的事已经完全确定了，一般会用现在时的 have (got) to，而不是 will have to。

I have (got) to pick up my daughter at school at four o'clock.

我得在四点钟去学校接我的女儿。

Sandra's got to be at the doctor's by three o'clock.

桑德拉三点钟之前必须到医生那里。

by 在（时间、日期）之前，早于……，不晚于……

by three o'clock 三点之前

也可以说

Sandra has to be at the doctor's by three o'clock.

Have you got to leave early tomorrow?

你明天得早点走吗？

Have got to 英国英语更常用，更日常口语，也有说 have got to 比 have to 语气更强一些。

She has got to study hard to pass the exam.
她必须努力学习才能通过考试。
这句也可以说
She has to study hard to pass the exam.

上节课的句子“你必须得交税。You have to pay tax. ”也可以说
You have got to pay tax.

Have to 和 have got to的语法变化规则是不一样的，像前面第907课讲 have 和 have got 的变化规则，have to 的 have 是实义动词，但 have got to 的 have 是助动词，变疑问句和否定句不需要助动词。

你必须得交税。
You have to pay tax.
You have got to pay tax.
—> 变疑问句
你必须得交税吗？
Do you have to pay tax?
Have you got to pay tax?
—> 变否定句
你不必交税。
You don't have to pay tax.
You haven't got to pay tax.

我们必须得脱鞋吗？
take off 脱（鞋，衣服等）
Do we have to take our shoes off?
Have we got to take our shoes off?

我们不必付食物的钱。/我们不必为食物买单。
We don't have to pay for the food.
We haven't got to pay for the food.

Have (got) to 用来表示客观的必须，可能是规则、规定、法律条例等。

You have to pay tax.
你必须交税。

We have to check everyone's ID.
我们必须检查每个人的身份证。
ID 身份证，身份证明（identification的缩写）

Have to 的 have 是实义动词，现在时态要变疑问句需要助动词 do 或 does，变否定句需要 don't 或 doesn't：
Do you have to vote in an election?
你必须在选举中投票吗？
vote 动词，投票，表决
election 名词，选举

He doesn't have to wear a uniform to school.
他上学不必穿制服。
uniform 制服

obligation
必须要做的事情，义务，责任，职责
英语中表达obligation会用像 must，have to，need to……

must
必须
①用于现在或将来必须做的事，不用于过去某个必须要做的事；
②通常是说话人认为这个事必须的（主观的必须）

You must do your homework every night.
你必须每晚做作业。

I must get some sleep.
我必须睡会儿觉。

I must buy some new clothes. Mine look so old.
我必须买一些新衣服。我的衣服看起来太旧了。

Must 是情态助词，所以不随主语人称变化而变化：
I must
you must
he must
she must
they must
后面直接跟动词原形。

will be able to

否定句用 won't 或 will not + be able to：

I won't be able to attend the meeting.

我将无法参加会议。
She will not be able to leave the office before 5pm.
下午5点之前她不能离开办公室。

疑问句就把 will 提到主语前面：
Will you be able to come to the party?
你能来参加聚会吗？

Will he be able to lift that box?
他能举起那个箱子吗？
lift 举起，抬起

请将上节课的6句话变成否定句和疑问句
① I will be able to attend the meeting tomorrow. 我明天可以参加会议。
② You will be able to enter the competition. 你将能够参加比赛。
③ He will be able to get the next flight. 他将能够坐下一班飞机。
④ She will be able to help you. 她会帮助你的。
⑤ We will be able to attend the wedding. 我们将能够参加婚礼。
⑥ They will be able to pass the exam. 他们将能够通过考试。

将来时，要表达将来能够做某事，不能用will can，可以用 will be able to。

I will be able to attend the meeting tomorrow.
我明天可以参加会议。

You will be able to enter the competition.
你将能够参加比赛。
enter 报名参加（比赛，竞赛，考试等）（进入，进来，进去）
competition 比赛，竞赛

He will be able to get the next flight.
他将能够坐下一班飞机。
get 搭乘，乘坐

She will be able to help you.
她会帮助你的。

We will be able to attend the wedding.
我们将能够参加婚礼。

They will be able to pass the exam.
他们将能够通过考试。

Be able to 的否定句

I'm able to attend the meeting. 我能参加会议。—> 
I am not able to attend the meeting.
我不能参加会议。

You're able to leave the country without a passport. 你可以在没有护照的情况下离开这个国家。—>
You aren't able to leave the country without a passport. 
没有护照你不能离开这个国家。

He's able to drive a car. 他会开车。—>
He isn't able to drive a car.
他不会开车。

She's able to read without glasses. 她不戴眼镜就能看书。—>
She isn't able to read without glasses.
她不戴眼镜就不能看书。

We're able to buy a new house. 我们能买个新房子。—>
We aren't able to buy a new house.
我们买不起新房子。

They're able to walk very far. 他们能走很远。—>
They aren't able to walk very far.
他们不能走很远。

Be able to 的过去时

把 be 变成 was/were —> was/were able to
I was able to come to your party.
[过去某时]我能来参加你的聚会。
I wasn't able to come to your party.
我没能来参加你的聚会。

We were able to leave on time.
[过去某时]我们能够准时离开。
on time 准时
We weren't able to leave on time.
我们没能准时离开。