can 和could 的不同用法（Can与Could的用法）

Can vs Could: How to Use the

我们来讨论一下情态动词can和could的用法。我们都知道能用英语表达做某事的能力或可能性有多重要，但英语语法可能很棘手。

而an和could是情态助动词，用来表达一种能力、许可、请求、提供或机会。在本文中，我们将探讨can和could之间的区别，以及如何使用它们。

Can vs. Could: 使用规则

Could 是Can的过去式

动词could主要是can的过去式。但它不仅仅是can的过去式:它还有其他can不具备的功能，例如，在第一件句中，参见英语条件从句的使用

例句

• She can speak Italian very well.
• I could swim, but I couldn’t ride a bike when I was nine years old.
• You can play with Amy after you do your homework.
• Could I have some tea?
• Can I carry your bags?
• We could go somewhere tonight.
• That can’t be true.
• You could get there in time if you hurried up.

表达感知动词的能力

Can和could也可以用来表示感知动词(看、听、感觉、味道、嗅觉等)的连续时态，以及理解、记住等动词。这些词分别是(see, hear, feel, taste, smell, like understand, remember)等。

例句

• Can you see the light over there?
• When I entered the room, I could hear something scratching.
• Harry put the keys in his pocket, but now he can’t find them.
• We couldn’t understand what the stranger was saying.

表面一般的能力

作为动词can的过去式，could在过去式和间接引语中用来表达一般能力。

例句:

• He said he could get that ticket for me.
• When I was younger, I could work out for two hours without stopping.

命令或要求某事

在请求、命令和句子中，使用could比can更礼貌。

例句：

• Do you think you could help me with this case?
• Can I use your phone?
• Could you do me a favour?
• Do the urgent task first, and then you can check the rest.

请求允许

当然，当我们请求许可时，最好使用动词can，因为could不能用来表示同意或拒绝同意

例句：

• Can I trust you? – Of course, you can.
• You can stay here if you want to.
• Can I have another cup of coffee? – No, I’m afraid you can’t.

You drank too much coffee.