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

Hello, I’m Oli.

Welcome to Oxford Online English.

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

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

lesson, which gives you an introduction to
the topic.

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

about ability.

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

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

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

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

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

For example: “She can speak Spanish very well.”

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

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

For example: “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.

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

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

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

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

and we need to use a different verb.

One of these verbs is ‘be able to’.

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

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

Spanish very well,” or: “She’s able to speak
Spanish very well.”

These two sentences have the same meaning.

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

was younger.”

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

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

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

‘could’ which you can use.

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

For example: “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.

We have to use ‘be able to’.

“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’.

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

There are many cases like this.

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

your sentence simpler and shorter.

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

it sounds more formal.

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

This gets a little bit more complicated.

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

Does it sound right to you?

What do you think?

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

not possible.

Do you know why?

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

the past.

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

You could say: “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.”

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

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

to’.

Let’s look at some more examples.

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

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

“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.

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

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

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

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

“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.”

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

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

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

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

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

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

and never be wrong.

Next, let’s look at ‘could’ in more detail.

‘Could’ has two meanings.

Look at two sentences: “I couldn’t help you
because I had too much to do.”

“I couldn’t help you even if I wanted to.”

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

Can you see the difference?

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

sentences?

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

In the first sentence, “I couldn’t help you
because I had too much to do,” the meaning

is past.

If we use ‘be able to’, we would say: “I wasn’t
able to help you because I had too much to

do.”

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

To use ‘be able to’, we would say, “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.

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

means.

For example: “Why couldn’t he do it last week?”

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

a past meaning.

“We could work together, if you wanted.”

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

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

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

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

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

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

don’t exist.

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

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

use ‘was/were able to’, or ‘managed to’.

Finally, ‘could’ can have two different meanings.

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

like ‘would be able to’.

OK, that’s the end of the lesson.

I hope it was useful for you.

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

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

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

OK, that’s all.

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

Bye bye!

大家好,我是奥利。

欢迎来到牛津在线英语。

在本课中,您可以学习如何使用情
态动词来表达能力。

如果您不知道情态动词是什么,或者
为什么要关心它们,请观看

本课,它会为您介绍
该主题。

所以在本课中,我们将专注于
使用动词“可以”和“可以”来

谈论能力。

您还将了解动词“
能够”和“设法”。

这些动词不是情态动词,但我们不能
在每种情况下都使用“可以”或“可以”来

谈论能力,所以有时我们需要
使用不同的非情态动词。

首先,我们来看看用“can”和
“could”来谈能力。

你可以用“can”来谈论
现在或未来的能力。

例如:“她的西班牙语说得很好。”

或者:“你周六可以和我们一起去吗?”

您也可以使用“could”来谈论
过去的一般能力。

例如:“我年轻的时候可以跑得更快
。”

“年轻的时候”是一种通用能力,
所以我可以随时跑得更快。

“她小时候会拉小提琴
。”

同样,这是过去较长时期的一般能力

这很简单,我相信你
对它很熟悉。

但是,在很多情况下
不能用“can”或“could”来谈论能力

,我们需要使用不同的动词。

其中一个动词是“能够”。

通常,“可以”和“能够”具有
相同的含义。

因此,您通常可以使用任何一个动词,而
在含义上没有任何区别:“她会说

西班牙语非常好”,或者:“她会说
西班牙语非常好”。

这两句话的意思是一样的。

“我年轻的时候可以跑得更快,”
或者:“我年轻的时候跑得更快

。”

同样,这两个句子之间的含义没有区别

但是,您不能在每个动词时态中都使用“可以”或“可以”

例如,如果您想使用现在的
完美形式,则没有可以使用的“可以”或

“可以”的形式。

因此,在这些情况下,您需要使用
“能够”的形式。

例如:“他从两岁开始就会游泳
。”

没有办法在这句话中使用“可以”或“可以”
并保持相同的含义。

我们必须使用“能够”。

“我喜欢能够选择自己的工作
时间。”

在动词’like’之后,我们需要一个带有
‘-ing’的动词,所以我们需要使用’be able to’。

同样,在这句话中无法使用“可以”或“可以”

像这样的情况很多。

一般来说,如果你有选择的话,
最好使用“can”或“could”,因为这会让

你的句子更简单、更短。

我们有时会选择使用“能够”,
即使“可以”或“可以”是可能的,因为

它听起来更正式。

好的,现在让我们看看过去的能力:
“可以”与“能够”。

这变得有点复杂。

让我们看一个例句:“
交通非常糟糕,但我们可以赶上我们的火车。”

你觉得对吗?

你怎么认为?

如果您说这听起来不对,那您实际上是对的
; 这句话不对,

不可能。

你知道为什么吗?

答案是这句话是在说过去
某个特定时刻的特定能力

在这种情况下,您不能使用 ‘could’; 你
需要使用不同的动词。

你可以说:“交通非常糟糕,
但我们赶上了我们的火车。”

或者:“交通非常糟糕,但我们
设法赶上了我们的火车。”

在这两个句子中,我们都在
谈论一瞬间,一列火车。

这是一个特定的情况; 这意味着我们不能
使用“可以”; 我们必须使用“能够”或“

设法”。

让我们再看一些例子。

“这是一项艰苦的工作,但我们设法按时完成了
一切。”

这意味着我们在特定的时刻完成了特定的事情

“我们的车在路上抛锚了,幸好
我修好了。”

我在特定时刻修复了它; 这
不是一般的事情。

这里还有一个更重要的点,这
使它变得更加复杂。

一般情况和特定情况之间的这种差异
仅适用于肯定句。

如果您的句子是否定的,则
“可以”和“能够”之间没有区别。

就像大多数其他情况一样:您可以选择
使用哪个动词,这并不重要。

“这是一项艰苦的工作,我们无法按时完成
所有工作。”

或者:“这是一项艰苦的工作,我们无法
按时完成所有工作。”

因为这些句子是否定的,所以
不管情况是一般的还是具体的;

现在可以使用两种形式:“不能”
或“不能”。

同样,在这种情况下,含义没有区别

因此,回顾一下,“可以/可以”或“能够”
通常具有相同的含义,除非您

谈论的是过去的特定情况
,并且句子是肯定的。

如果您对此不确定,请记住,您
始终可以在任何情况下使用“能够”

并且永远不会出错。

接下来,让我们更详细地看一下’could'。

“能”有两层意思。

看两句话:“我帮不了你,
因为我有太多事情要做。”

“就算我愿意,我也帮不了你。”

在这两个句子中,动词“可以”
以不同的方式使用。

你能看到区别么?

这里有一个问题来检查您的理解:
您将如何在这两个句子中使用“能够”

如果您想考虑答案,请
暂停视频并考虑一下。

在第一句话中,“我无法帮助你,
因为我有太多事情要做”,意思

是过去。

如果我们使用“能够”,我们会说:“我
无法帮助你,因为我有太多事情

要做。”

在第二句中,“可能”具有假设
或条件意义。

要使用“能够”,我们会说,“即使我愿意,我也
无法帮助你。”

所以“可能”可以有两种不同的含义;
过去的意义和假设的意义。

您需要使用句子的上下文
或情况来理解“可能”的

含义。

例如:“为什么他上周不能这样做?”

时间标记“上周”向您显示
这句话已经过去,而“可能”

具有过去的含义。

“如果你愿意,我们可以一起工作。”

同样,带有“if”的句子结尾向
您表明“could”具有假设的含义。

好的,让我们回顾一下
这节课的重点。

您可以使用“can”或“could”来谈论
过去、现在或未来的能力。

“可以/可以”和“能够”通常
具有相同的含义。

有时您需要使用“能够”,
例如,如果您需要使用带有“-ing”的动词,

或者如果您需要使用现在完成
时,或者“可以/可以”不使用的其他时态

存在。

在过去,“可以”和“曾经/能够”
有时是不同的。

如果您在谈论特定情况,
并且句子是肯定的,则只能

使用“was/were able to”或“managed to”。

最后,“可能”可以有两种不同的含义。

它可以具有过去的含义,与“曾经/
能够”相同,也可以具有假设的含义,

例如“将能够”。

好的,这节课到此结束。

我希望它对你有用。

如果您想查看本课程的完整版本
,可以在我们的网站上查看。

完整的课程包括文本,因此您可以
阅读和复习所有内容。

还有一个测验可以帮助您练习该
主题并检查您是否理解了所有内容。

好的,仅此而已。

再次感谢您的观看,我们
下期再见。

再见!