How to Use Can, Could and Be Able To - English Modal Verbs for Ability

英语语法 - 情态动词 能力

Hello, I'm Oli.

您好，我是Oli。

Welcome to Oxford Online English.

欢迎来到Oxford Online English。

In this lesson, you can learn about using modal verbs to express ability.

在本节课里，您可以学习使用 情态动词来表达能力。

If you don't know what modal verbs are, or why you should care about them, watch this

如果您不知道情态动词是什么， 或者为什么您必须留意它们，

lesson, which gives you an introduction to the topic.

看可以给您一个介绍 本主题的这个课程。

So in this lesson, we're going to focus on using the verbs 'can' and 'could' to talk

所以在这节课，我们会关注 使用动词“can‘和”could“来

about ability.

谈论能力。

You will also learn about the verbs 'be able to' and 'managed to'.

您也会学习动词”be able to“ 和”managed to“。

These verbs are not modal verbs, but we can't use 'can' or 'could' in every situation to

这些动词不是情态动词，但是我们不能 在每一种情形下使用”can“或

talk about ability, so we sometimes need to use a different, non-modal verb.

”could“去谈论能力，所以我们有时 需要使用不同的、非情态动词。

First of all, let's look at using 'can' and 'could' to talk about ability.

首先，我们看看使用”can“和 ”could“来谈论能力。

You can use 'can' to talk about abilities in the present or the future.

您可以使用”can“现在式或 将来式来谈论能力。

For example: "She can speak Spanish very well."

例如：”She can speak Spanish very well.“

Or: "Can you come with us on Saturday?"

或者：”Can you come with us on Saturday?“

You can also use 'could' to talk about general abilities in the past.

您也能使用”could“过去式 来谈论一般能力。

For example: "I could run much faster when I was younger."

例如：”I could run much faster when I was younger.“

'When I was younger' is a general ability, so I could run faster any time I wanted.

”When I was younger“是一般能力， 所以我随时都可以跑得很快。

"She could play the violin when she was a child."

”She could play the violin when she was a child.“

Again, this is a general ability about a longer period in the past.

同样，这是一个在过去 长期有的一般能力。

This is quite simple, and I'm sure you're familiar with it.

这十分简单，以及 我确定您了解它。

However, there are many situations where you can't use 'can' or 'could' to talk about ability,

然而，有很多您不能使用”can“或 ”could“来谈论能力的情形，

and we need to use a different verb.

我们需要使用不同的动词。

One of these verbs is 'be able to'.

这些动词中的一个是"be able to"。

Generally, 'can' and 'be able to' have the same meaning.

通常来说，”can“和”be able to“ 有相同的意思。

So, you can usually use either verb without any difference in meaning: "She can speak

所以，您可以常用任何一个动词而没有 任何含义上的差别：”She can speak

Spanish very well," or: "She's able to speak Spanish very well."

Spanish very well," 或：“She's able to speak Spanish very well.”

These two sentences have the same meaning.

这是两个有相同意思的句子。

"I could run much faster when I was younger," or: "I was able to run much faster when I

“I could run much faster when I was younger,” 或：“I was able to run much faster when I

was younger."

was younger.”

Again, there's no difference in meaning between these two sentences.

同样，在这两个句子之间 没有意思上的差别。

However, you can't use 'can' or 'could' in every verb tense.

然而，您不能在每一个动词 时态使用“can”或“could”。

If you want to use, for example, the present perfect form, there's no form of 'can' or

如果您想用，例如，现在 完成式，没有

'could' which you can use.

您能用的“can”或”could“。

So in these cases, you need to use a form of 'be able to'.

那么在这些事例中，您需要使用 ”be able to“的一个形式。

For example: "He's been able to swim since he was two years old."

例如：”He's been able to swim since he was two years old.“

There's no way to use 'can' or 'could' in this sentence and keep the same meaning.

在这个句子里，没办法使用”can“或 ”could“并保留相同的意思。

We have to use 'be able to'.

我们必须使用”be able to“。

"I like being able to choose my own working hours."

”I like being able to choose my own working hours.“

After the verb 'like', we need a verb with '-ing', so we need to use 'be able to'.

在动词”like“之后，我们需要一个带”-ing“的动词， 这样我们需要使用”be able to“。

Again, there's no way to use 'can' or 'could' in this sentence.

同样，没办法在这个句子里 使用”can“或”could“。

There are many cases like this.

有很多类似这样的例子。

Generally, if you have a choice, it's better to use 'can' or 'could', because it makes

通常来说，如果您有一个选择，最好是使用 ”can“或”could“，因为它

your sentence simpler and shorter.

会让您的句子更简单并更短。

We sometimes choose to use 'be able to', even when 'can' or 'could' are possible, because

我们有时选择使用”be able to“，即使在 ”can“或”could“可以用时，因为

it sounds more formal.

那听上去更正式。

OK, now let's look at ability in the past: 'could' vs. 'be able to'.

好，现在过去时态下的能力： “could” vs“be able to”。

This gets a little bit more complicated.

这有点复杂。

Let's look at an example sentence: "The traffic was really bad, but we could catch our train."

我们来看一个例句：“The traffic was really bad, but we could catch our train.”

Does it sound right to you?

那听起来对吗？

What do you think?

您怎么想？

If you said it sounds wrong, you're actually correct; this sentence is not right, it's

如果您说听起来是错的，您实际上是 正确的；这个句子不正确，

not possible.

那是不可能的。

Do you know why?

您知道为什么吗？

The answer is this sentence is talking about a specific ability at a specific moment in

在这个句子里的回答是在谈论 一个在过去的特定

the past.

时刻的特定能力。

In this case, you can't use 'could'; you need to use a different verb.

在这个事例里，您不能使用“could”； 您要用一个不同的动词。

You could say: "The traffic was really bad, but we were able to catch our train."

您可以说：“The traffic was really bad, but we were able to catch our train.”

Or: "The traffic was really bad, but we managed to catch our train."

或者：“The traffic was really bad, but we managed to catch our train.”

In both of these sentences, we're talking about one moment, one train.

在这两个句子，我们在谈论 一个时刻、一部火车。

It's a specific situation; that means we can't use 'could'; we must use 'be able to' or 'managed

那是一个特定的情形；那意味着我们不能用 “could”；我们必须用“be able to”

to'.

或者“managed to”。

Let's look at some more examples.

我们来看一些例子。

"It was hard work, but we managed to finish everything on time."

“It was hard work, but we managed to finish everything on time.”

That means we finished something specific, at a specific moment.

那意思是我们在特定时刻完成了 某些特定的事情。

"Our car broke down on the way, but luckily I was able to fix it."

"Our car broke down on the way, but luckily I was able to fix it."

I fixed it at a specific moment; it wasn't a general thing.

我在某个特定的时刻修好它；那 不是一件一般的事情。

There's one more important point here, which makes it even a little bit more complicated.

在这里，有一个要点，甚至让它 变得有一点更复杂。

This difference between general and specific situations only applies to positive sentences.

一般情形和特定情形之间的 区别仅适用于肯定句。

If your sentence is negative, there's no difference between 'could' and 'be able to'.

如果您的句子是否定的， “could”和 “be able to”之间没有区别。

It's like most other cases: you can choose which verb to use and it doesn't matter.

那就像大多数的事例：您能选择 用哪一个动词，那没有问题。

"It was hard work, and we couldn't finish everything on time."

"It was hard work, and we couldn't finish everything on time."

Or: "It was hard work, and we weren't able to finish everything on time."

或者： "It was hard work, and we weren't able to finish everything on time."

Because these sentences are negative, it doesn't matter if the situation is general or specific;

因为这些句子是否定的，无论情形是一般的 或特定的，它都没有问题；

it's now possible to use both forms: 'couldn't' or 'weren't able to'.

用两个形式也是可能的：“couldn't” 或“weren't able to”。

Again, there's no difference in meaning in this case.

同样， 在这个例子， 意思上没有区别。

So, to review, 'can/could' or 'be able to' generally have the same meaning, unless you're

那么，来复习一下，“can/could”或“be able to” 通常有相同的意思，除非您

talking about a specific situation in the past, and the sentence is positive.

在谈论一个过去的特定情形， 句子是肯定式。

If you're not sure about this, remember you can always use 'be able to' in every case

如果您不确定这个，记住您总是 能在每件事上使用“be able to”

and never be wrong.

并从来都不会错。

Next, let's look at 'could' in more detail.

接下来，我们看看“could”的更多细节。

'Could' has two meanings.

“Could”有两个意思。

Look at two sentences: "I couldn't help you because I had too much to do."

看两个句子：“I couldn't help you because I had too much to do.”

"I couldn't help you even if I wanted to."

"I couldn't help you even if I wanted to."

In these two sentences, the verb 'could' is used in different ways.

在这两个句子里，动词“could” 被用不同的方式使用。

Can you see the difference?

您能找出区别吗？

Here's a question to check your understanding: how would you use 'be able to' in these two

有一个问题来测您的理解： 您怎么在这两个句子里

sentences?

使用“be able to”？

If you want to think about your answer, pause the video and think about it.

如果您想考虑您的回答，暂停 视频并考虑它。

In the first sentence, "I couldn't help you because I had too much to do," the meaning

在第一个句子："I couldn't help you because I had too much to do,"

is past.

意思是在过去的。

If we use 'be able to', we would say: "I wasn't able to help you because I had too much to

如果我们使用“be able to”，我们要说："I wasn't able to help you because I

do."

had too much to do.“

In the second sentence, 'could' has a hypothetical or conditional meaning.

在第二句，”could“有一个假想 或条件的意思。

To use 'be able to', we would say, "I wouldn't be able to help you even if I wanted to."

要使用”be able to“，我们要说，”I wouldn't be able to help you even if I wanted to.“

So 'could' can have two different meanings; a past meaning and a hypothetical meaning.

所以”could“能有两个不同的意思； 一个过去意思和一个假想意思。

You need to use the context of the sentence or the situation to understand what 'could'

您要用句子的上下文或环境 来理解”could“是什么

means.

意思。

For example: "Why couldn't he do it last week?"

例如："Why couldn't he do it last week?"

The time marker 'last week' shows you that this sentence is past, and that 'could' has

时间标识”last week“显示您这个 句子是过去式，”could“有

a past meaning.

一个过去的意思。

"We could work together, if you wanted."

"We could work together, if you wanted."

Again, the end of the sentence with 'if' shows you that 'could' has a hypothetical meaning.

同样，句尾带”if“的句子告诉您 ”could“有一个假想的意思。

OK, let's review the important points from this lesson.

好，我们来复习本节课的重点。

You can use 'can' or 'could' to talk about abilities in the past, present or future.

您可以使用”can“或”could“来谈论 过去、现在或将来的能力。

'Can/could' and 'be able to' usually have the same meaning.

”Can/could“和”be able to“ 通常有相同的意思。

Sometimes you need to use 'be able to', for example if you need to use a verb with '-ing',

有时，例如，如果您用一个带”-ing“ 的

or if you need to use the present perfect tense, or some other tense where 'can/could'

动词，或是如果您需要用现在完成 时态，或一些其他的”can/could“

don't exist.

不存在的时态，您要用”be able to“。

In the past, 'could' and 'was/were able to' are sometimes different.

在过去式，”could“和”was/were able to“ 有时是不同的。

If you are talking about a specific situation, and the sentence is positive, you can only

如果您在谈论一个特定的环境， 句子是肯定的，您仅能

use 'was/were able to', or 'managed to'.

使用”was/were able to“或”managed to“。

Finally, 'could' can have two different meanings.

最后，”could“可以有两种不同的意思。

It can have a past meaning, the same as 'was/were able to', or it can have a hypothetical meaning,

它可以有过去的意思，与”was/were able to“相同，或它有一个假想的意思，

like 'would be able to'.

像是”would be able to“。

OK, that's the end of the lesson.

好，本节课到此结束。

I hope it was useful for you.

我希望它对您有用。

If you want to see the full version of this lesson, you can check it out on our website.

如果您想看本节课的完整版本， 您可以看一下我们的网站。

The full lesson includes a text, so you can read and review everything.

全部的课程包括文字，所以您可以 读并复习每一样东西。

There's also a quiz to help you practise the topic and check that you've understood everything.

也有一个随堂测验来帮您练习这个 主题，并检查您明白了所有的东西。

OK, that's all.

好，就到这。

Thanks again for watching, and I'll see you next time.

再次感谢观看，下次见。

Bye bye!

再见！