官方APP下载:英语学习播客(支持苹果手机、安卓手机)
创办于2003年
UNSV记不住?那就记中文谐音“忧安思危”吧!
  Slow and Steady Wins the Race!
UNSV英语学习频道 - Slow and steady wins the race!
公众微信服务号
英语全能特训(微信公众服务号)
UNSV英语学习频道淘宝网店
客服短信:18913948480
客服邮箱:web@unsv.com
初级VIP会员
全站英语学习资料下载。
¥98元/12个月

Can and Be Able To

作者:Alice Bryant 发布日期:1-5-2019

Modal verbs are helping verbs. We use them with main verbs to help us express ability, possibility, necessity and permission. Today's question is about a modal that is commonly confused with an expression. Here's the question, which comes from a listener named Cafer:

Question

Hi! Would you like to explain the difference between "can" and "be able to"? Thank you. -Cafer Özcan​

Answer

Hi, Cafer!

I can explain the differences between the two.

I just used "can" to talk about my ability to do something. We also use "be able to" for abilities, but usually only when "can" is not possible. I'll tell you what that means in a minute.

But first, let's explore the word "can."

Can

"Can" is a modal verb. We use it to:

  • talk about present or future ability or possibility

    I can play the guitar.

    You can buy the tickets online.

You must use "could" for the past tense, such as in, "You could have bought the tickets online."

We also use "can" to:

  • ask for or give permission​

    I am finished. Can I go now?

    Yes, you can.

  • and to ask someone to do something​

    Can you bring me the magazine?

Be able to

Now, let's explore "be able to."

This expression is not a modal. It is the verb "to be" plus the adjective "able." The word "to" shows that an infinitive verb will follow.

We use "be able to":

  • when it is not possible to use "can" for abilities, such as after other modal verbs​

    I won't be able to take you to the train station. Sorry!

    You should be able to finish the book in a few days.

The words "won't", short for "will not", and "should" are modals. In English, we do not put two modals together. So, we cannot put "can" after them.

We also use "be able to":

  • to talk about small or large past successes.​

    We were able to get a great price on the television.

    She was able to win the math competition last month.

  • But in negative form, we can use 'be able to" or "could":​

    We couldn't get a great price on the television.

    She wasn't able to win the math competition last month.

But note that the negatives 'wasn't able to' and 'weren't able to' are a little more formal than 'couldn't.'

And that's Ask a Teacher.

I'm Alice Bryant.

Do you have a question for Ask a Teacher, write to us in the comments area. Be sure to tell us what country you are from.

Words in This Story

confusev. to make someone unable to understand something

guitarn. a musical instrument that is held against the front of your body and that has six strings

infinitiven. the basic form of a verb

negativeadj. describing a word or statement that means "no" or that expresses a denial or refusal

版权所有©2003-2019 南京通享科技有限公司,保留所有权利。未经书面许可,严禁转载本站内容,违者追究法律责任。 互联网经营ICP证:苏B2-20120186
网站备案:苏公网安备 32010202011039号苏ICP备05000269号-1中国工业和信息化部网站备案查询
广播台