在公众号输入关键字"英语单词"或是"yydc"可跳转到该文章。 一、can的过去式:用来表示过去的能力、可能性或允许,否定式是:couldn't 或 could not。
I could run faster then. 那时我能跑得更快. She said that she couldn't come. I couldn't hear what they were saying.Sorry, I couldn't get any more.It could be no better at that time.Only men could go to the club in those days. 在当时,只有男人可以去俱乐部。Don't worry─they could have just forgotten to call.二、委婉的提出问题或陈述看法,这时,could和can没有时间上的差别。可以用can,只是用could更客气,谦虚和委婉一些。Could you please do it for me ?Could you babysit for us on Friday? I could be wrong. Could you come over here? 我也许错了。你能到这边来吗?It could be about 4:30 p.m.We could write a letter to the director.You could always try his home number.If he worked hard last week, he could finish the work.---->这是真实条件句,其主句的could指将来,语气更加委婉一些。If he had worked hard, he could have finished the work.---->这是假设句实际上他过去并没有在努力的工作,
所以他未能完成那项工作。五、could have + 过去分词:表示现在对过去事物的判断,可译为本来能够或者本来可以,暗指当时未实现的动作。They could have let me know they were going to be late!Anyone could have drugged that wine. You could have been killed! He could have taken a spare key.
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