| 词组 | be able to |
| 释义 | Contents overview be able toable: be able toable: be able to be able to 8510016be able tobe able to 8510212unableunable 851185785 be able toWe use able especially in the structure be able to + infinitive. This often has the same meaning as can (82). There is a negative form unable.Some people are able to / can walk on their hands.I am unable to / can't understand what she wants.Can is preferred in the sense of 'know how to', and in expressions like can see, can hear, etc (84).Can you knit? (More natural than Are you able to knit?)I can see a ship. (More natural than I am able to see a ship.)Be able to is used most often for people or other living things. Compare:Jake can lift / is able to lift 150 kilos.This crane can lift 30 tonnes. (More natural than This crane is able to lift 30 tonnes.)Be able to is used in cases (e.g. future, present perfect) where can/could is not grammatically possible because it has no infinitive or participles (68.1).One day scientists will be able to find a cure for cancer. (not … will can find …)What have you been able to find out? (not What have you could …?)I might be able to help you. (not I might can …)Able is not often followed by passive infinitives.He can't be understood. (More natural than He's not able to be understood.)For differences between could and was able to, 82.4, 83.2.Previous Next |
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英语用法大全包含1354条英语用法指南，基本涵盖了全部常用英文词汇及语法点的翻译及用法，是英语学习的有利工具。