一、情态定义
情态动词+动词原形（不处理动词）
整体是一个谓语动词。
特点：
- 情态动词的时态变化有限
- 情态动词没有人称变化
二、情态使用
- Children may face serious difficulties...
- Today, the virtue of work may be a bit overblown. may be 谓语动词
maybe 副词，修饰动词/句子，“可能，也许:
Maybe I can show you the way.
三、情态动词的时态
- 现在
- 过去
| 现在时 | 过去时 |
|---|---|
| must | 无 |
| can | could |
| will | would |
| shall | should |
| may | might |
过去时含义：
- 表示过去
- 不表示过去，表示现在的更委婉语气
- 用于虚拟语气
Can you help me now?
Could you help me now?
四、情态动词表示情态
1.must 必须
- To some extent the housing sector must shoulder the blame.
2.can/could 能够
- They can also learn geometry by assembling a bicycle.
- In the past, workers with average skills.. could earn an average lifestyle.
3.will/would 愿意/将要
- Will you marry me?
- some will be less effective than others.
- In effect, the approach would create a “walled garden” in cyberspace...
4.may/might 可以/可能
- May I help you?
- guilt may compensate for an emotional deficiency.
- We might then begin to solve our immigration challenges.
5.should 应该
- Should they become charitable corporation?
- ...I should have deep work scheduled for roughly the next month.
五、情态动词表示推测
可能性最高：must 肯定 一定
可能性一般：may/might can/could should... 可能 也许
可能性较低：can't couldn't 不可能
- other suits may have an even greater impact.
- Such a move could affect firms such as McDonald's...
推测不同时间：
- 情态动词 + do 推测现在
- 情态动词 + be doing 推测现在正在进行
- 情态动词 + have done 推测过去
eg：
- It must have rained yesterday.昨天肯定下雨了
- She must have cried.
- Jealousy and anger..may have evolved to alert us to important inequalities.
- They may be coming [into the workforce]...
词组：have to / ought to + do
..Google has to maintain vast data centres around the world...
六、语态
- 主动语态：I eat apples.
- 被动语态：Apples are eaten.
1.被动语态构成
be+done
- be：被动的时间、主语的单复数
- done：被动的动作
eg：
But her appeal was considered a failure...
强调被谁做：
- The shortage is compounded by federal immigration raids...
2.被动语态与时态结合
但是她的呼吁（过去）被认为是失败的：
But her appeal was considered a failure.
但是她的呼吁（现在）被认为是失败的：
But her appeal is considered a failure.
但是她的呼吁将会（现在的将来）被认为是失败的：
But her appeal will be considered a failure.
但是她的呼吁过去将会（过去的将来）被认为是失败的：
But her appeal would be considered a failure.
但是她的呼吁过去正在被认为是失败的：
But her appeal was being considered a failure.
但是她的呼吁现在正在被认为是失败的：
But her appeal is being considered a failure.
但是她的呼吁过去已经（过去的之前）被认为是失败的：
But her appeal had been considered a failure.
但是她的呼吁现在已经（现在的之前）被认为是失败的：
But her appeal has been considered a failure.
3.被动语态与情态结合
情态动词 + be + done
- Obesity can be divided into moderately obese, severely obese, and very severely obese.
- Their success may be determined by a suit
- sustainability-oriented values must be expressed through everyday action and choice.
七、谓语动词的否定
1.实义动词变否定
有实际意义的动词
did/do/does + not + 动词原形
- I liked music. I did not like music.
- I like music. I do not like music.
- He like music. He does not like music.
eg:
- A few decades ago, many people didn't drink water outside of a meal.
- We don't need more categories.
- a gap year does not hinder the success of academic pursuits.
2.非实义动词变否定
直接加not变否定
例如：be动词，情态动词，完成时态中的have/has/had等
- Thinner isn't always better.
- Money may not quite buy happiness...
- It has not been much fun.
- I will not be waiting for you.（既有情态动词又有be动词，not放情态动词后面）
八、谓语动词的强调
do/does/did + 动词原形
I trust you.
I do trust you. He does trust you.
eg：
- The zone do deliver some improvements to air quality..
- But science does provide us with the best available guide to the future...
- The number of adults doing weekly sport did rise, by nearly 2 million in the run-up to 2012 ...
