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cover of episode Throwback Thursday S1 #98 - Could Have, Should Have, Would Have (And Negatives)

Throwback Thursday S1 #98 - Could Have, Should Have, Would Have (And Negatives)

2025/3/13
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Learn English | EnglishClass101.com

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Alisha: 本节课讲解情态动词could have, should have, would have 的含义、否定形式和区别。首先,could have 的肯定式表示过去可能发生的事情,例如:'If I had known you were throwing a surprise party, I could have helped.' 否定式could not have 表示过去不可能发生的事情,例如:'No, that couldn't have been Sarah in the cafe just now. She's at the office.' 需要注意的是,could have 只表达可能性,不涉及计划或遗憾。 接下来是should have。肯定式表达对过去未做之事感到后悔,例如:'I should have studied more when I was in school.' 这里表达的是说话人过去学习不够,现在感到后悔。否定式should not have 表示对过去已做过的事情感到后悔,例如:'I shouldn't have spent so much time playing video games when I was a kid.' 这里表达的是说话人过去玩游戏时间太多,现在感到后悔。 最后是would have。肯定式表示过去未实现的计划,例如:'I would have arrived on time today, but there was terrible traffic, so I did not arrive on time.' 这里表达的是说话人本来计划准时到达,但因为交通堵塞而未能如愿。否定式would not have 表示过去未实现的计划或愿望的缺乏,常用于给出建议时谈论他人的选择,例如:'If I were you, I wouldn't have quit my job before I found a new position.' 这里表达的是如果我是你,我不会在找到新工作之前就辞职。 总而言之,could have 表示可能性,should have 表示遗憾,would have 表示计划或愿望。这三个表达及其否定形式非常相似,但表达的侧重点不同,需要根据语境仔细辨析。

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This chapter explores the meaning and usage of "could have" in its positive and negative forms. It focuses on expressing past possibilities, differentiating it from plans or regrets. Examples illustrate how "could have" describes actions that were possible but didn't happen.
  • Positive 'could have' expresses past possibilities
  • Negative 'could not have' expresses past impossibilities
  • Focuses solely on possibility, not plans or regrets

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中文

Hi everybody, my name is Alisha. In this lesson I'm going to talk about could have, should have, and would have, what they mean, how to use them in the negative, and the differences between them. So, let's get started. First, I want to begin with could have. Let's look at the positive and the negative meanings of could have.

First, positive. We use could have, positive, for something that was possible in the past. So, to give kind of an image of this, if our conversation is happening now, when we use could have, we're talking about something that had possibility in the past. Something we were able to do, for example.

An example sentence: If I had known you were throwing a surprise party, I could have helped. I could have helped. So here, could have shows us that this action, helping,

was possible in the past. In this case, the speaker did not know some information and as a result this action did not happen but it was possible at a point in the past. The speaker could have helped. Helping was a possibility in the past. So we use could have to express that possibility. The negative form however expresses the opposite. So in the negative, could

not have expresses something that was impossible, impossible, so not possible in the past. So here if we want to give an image, it's something that was not possible, something we were not able to do. Let's look at an example of this.

No, that couldn't have been Sarah in the cafe just now. She's at the office. So here, I'm using couldn't have, could not have, contracted, reduced, becomes couldn't. So, that couldn't have been Sarah in the cafe just now. In other words, it's impossible that just now we saw Sarah in the cafe. Why?

She's at the office. So in this case, maybe Sarah is the speaker's colleague, co-worker. So we know Sarah is at the office. So we saw someone maybe who looks like Sarah at the cafe just now. But it's not possible it was Sarah because Sarah's at the office. So we can say that couldn't have been. So it's impossible that that was Sarah.

So, "couldn't have been" sounds much more natural than "It's impossible that that was Sarah." So we use "couldn't have been."

or could not have been. So positive form, something that was possible in the past. So be careful in maybe contrast, a key difference here is this is only about possibility. We're not talking about like a plan to do something or regret necessarily. We're only talking about possibility when we use could or could not here.

So, with this, let's move along to the next part. The next part, I want to focus on "should have". So, let's look at the positive form. "Should have" in the positive expresses regret for something we did not do in the past. So, an image of this here: If our conversation is happening now, we want to talk about something

we did not do in the past and that now maybe we think, "Oh, it's a good idea." Like, "I should have done this thing." I did not do this thing in the past. That's why I marked it with an X here. So, I did not do this thing, but I feel bad now. I feel regret. Like, I should have done that thing in the past. So, an example sentence of this:

I should have studied more when I was in school. Here is the should have. I should have, and this action, studied more.

So, in other words, the speaker did not study enough in the past. The speaker feels he or she did not study enough in the past, regrets that, and wants to express the change. Like, I wish I had done this thing. I should have studied more when I was in school. So here we have more. This is a common pattern with should have or should not have.

When we use more, it means I should have studied more than I did when I was in school. So here, the speaker is expressing regret, sadness about something they did not do.

Therefore, when we use the negative form, the speaker, again, expresses regret, yes, but they're expressing regret for something that happened in the past, something they did in the past. So I've marked it here with a check. This action did happen and we feel regret about that action. We feel bad about something we did in the past. An example.

"I shouldn't have spent so much time playing video games when I was a kid." So here, I've used "shouldn't have," so "should not have" is how we make the negative form. I've reduced it "shouldn't have," "shouldn't've" in rapid speech, "shouldn't've." "I shouldn't have spent so much time playing video games." So, what's the action here? The speaker played video games when he or she was a child.

The speaker now regrets that. The speaker says, "I shouldn't have spent so much time." "I should have spent less time playing video games." So I could use positive "should have." "I should have spent less time playing video games when I was a kid."

Here, "I shouldn't have spent so much time." So here, a key point with "should have" is that we're expressing regret. Remember, with "could have" we're talking just about possibility. With "should have" we're expressing a regret for something that did or did not happen in the past. So, with this in mind, let's go on to the last point for this lesson. The last point, the last point rather is "would have", "would have".

So, when we say "would have", we often say "would've", "would've". I mentioned it here with "should have", we say "should've" or "shouldn't've". Same thing with "could have", like "could've" or "couldn't've" is the correct pronunciation in fast speech. So, when we talk about "would have" or when we look at "would have", and we look at the positive form,

We use it to express a plan for something that did not happen. So we're talking about something in the past. So from a point in the past, something in the future at that time, we had a plan for that thing or we thought something was going to happen. But in the positive form, it did not happen. This is kind of tricky. Let's look at an example situation. Here.

I would have arrived on time today, but there was terrible traffic, so I did not arrive on time.

So first, here's my action: I would have arrived on time. So I had a plan or I had a desire. I was thinking I was going to arrive on time. So at this point in time, I would have arrived on time today. Maybe we're thinking when I left the house, maybe this is where the action starts. My plan was to arrive on time. So again, this is all happening in the past. My conversation is here.

I was planning to arrive on time, but there was terrible traffic. Terrible traffic means lots and lots of cars. It was difficult to drive or difficult to get to work. So, I did not arrive on time. I would have arrived on time, but I didn't because of terrible traffic. So this shows us, this would have shows us,

All of this information, everything here happened in the past on like a timeline. So I thought I was going to arrive on time, something happened and I didn't. So we can use would have to show like our thinking in this point, would have in the past, about a future action that is also in the past. So a couple of past points there at the same time. Okay.

So let's compare this then to the negative form. The negative form then expresses the opposite. So we have a lack of plan or a lack of a desire. So lack of something means no plan or no desire. So lack of plan for something that happened in the past. It did happen, yes.

So, we commonly use both of these to talk about other people's choices, like when we're giving advice. This example sentence is a very common way that we use "would not have" or "wouldn't've". Let's look. If I were you,

"I wouldn't have quit my job before I found a new position." So here is my "would not have." I've reduced it to "wouldn't have." "I would not have quit my job before I found a new position." So that means, "If I were you..." This is how we're beginning this. This is a very common way that this "would have" or "would not have" is used.

So, if I were you, I'm not you, but if I were, at this point in time in the past, my decision would not have been to quit my job.

However, your decision was to quit your job. This did happen. You quit your job. In my case, I would not have done that. So here, in opposite to the positive form, I'm talking about a point in the past, like if I were you, just in general, and I'm talking about a future decision I might make.

In this case, the person listening did choose to quit his or her job. I'm saying, "I would not have quit my job. That would not have been my decision for the future." So again, there's kind of this idea of two points in the past, like a kind of a general, I guess, a starting point in the past, if I were you in this case, and some decision, some plan, some like desire or lack of desire in this case in the negative form.

So we use these, like I said, to talk about like other people's choices when we're giving advice. Like, "Oh, if I were you, I would have done this in the past."

So, we use would have to talk about past decisions and maybe to talk about things like if you were the speaker, like things you might change, what would you do differently? So, we use this to talk about these sorts of past decisions and give advice and talk about how we might make different decisions in the future.

This kind of expresses a desire or lack of desire. This one should have expresses regret in the past. Could have expresses possibility. So this is just a quick introduction to the differences between these three expressions and their negative forms. I didn't write the not here, so would not have.

But if you have any other questions about this, please let us know in the comments. They are very similar, I know. They sound very similar and it can be hard to understand how to use them, but try to keep these three kind of themes in mind: possibility and regret and then kind of desire or advice here.

So I hope that this helps you understand the differences between these three. If you have questions or comments or if you want to practice making an example sentence, please feel free to do so in the comment section of this video. Thanks very much for watching this lesson and I will see you again soon. Bye-bye.