Could or could have done

[Rachel Adams]

Is it wrong to use "could not" instead of "could not have done" in these sentences? These examples are from "Essential Grammar in Use" by Raymond Murphy.

1. "Ken's aunt wanted him to drive her to the airport on Tuesday. He couldn't have driven her to the airport (because his car had been stolen.)"

2. "Jack wanted Ken to lend him £50 last week. He couldn't have lent Jack £20."

3. "Jane wanted Ken to come to her party on Saturday evening. He couldn't have come to Jane's party."

I have read different discussions. I also asked this Something on another forum. native speakers don't agree with the book's examples.
https://forum.wordreference.com/threads/could-not-or-could-not-have-done.3832837/#post-19584005

 

[5jj]

I am not going to go back and forwards between this and another forum in order to contribute to this thread. If you want us to discuss your four (!) sentences here, you need to tell us what Murphy said about these sentences.

 

[Rachel Adams]

Murphy suggests using only "could have done" in them. But native speakers say "could" is also possible. I am lost.

https://www.usingenglish.com/forum/threads/204550-couldn-t-do-vs-couldn-t-have-done

I found this discussion on UE. I have been reading different discussions. Perhaps I am worrying too much and either can be used as it is explained in this discussion I provided the link for.

 

[emsr2d2]

I would use "He couldn't drive/He couldn't lend/He couldn't come".

 

[Rachel Adams]

I would use "He couldn't drive/He couldn't lend/He couldn't come".

Then why do textbooks confuse learners by saying only "could have done" is correct? I wrote this example: "If I had had time I could have written two reports." I was told by a native speaker that it's a strange sentence but it's correct. I used it because in Michael Swan's "Practical English Usage" I read "we use "could have.. to talk about unrealised past ability or opportunities-to say that somebody was able to do something, but didn't do it, or that something was possible , but didn't happen. No mention of "could" again. And one of his examples: "I could have won the race if I hadn't fallen."

 

[Charlie Bernstein]

We don't know the context of those sentences. When we use "couldn't have" that way, it usually means we're disagreeing with someone:

- Me: I think I met you at the University of Iowa.

- You: No, you couldn't have. I've never been to Iowa.

That fits #1. We know that because you gave us some context. On 2, 3, and 4, it depends.

 

[Charlie Bernstein]

Then why do textbooks confuse learners by saying only "could have done" is correct?

> I don't know. You don't always need "done" after "could have":

> You: Did you eat the last brownie?

> Me: Oops. I could have. Was that the last brownie? Sorry.

I wrote this example: "If I had had time I could have written two reports."

> That's fine.

I was told by a native speaker that it's a strange sentence

> I don't agree.

but it's correct.

> Yes, it is.

I used it because in Michael Swan's "Practical English Usage" I read "we use 'could have' [Put quotation marks on both sides of quotes; alternate between double and single quotes when a quote includes another quote.] to talk about unrealised past ability or opportunities-to say that somebody was able to do something, but didn't do it, or that something was possible[no space], but didn't happen.

> That is true.

No mention of "could" again.

> Should there have been?

And one of his examples: "I could have won the race if I hadn't fallen."

> That's fine, too.

I don't think Swan is trying to teach you every little quirk of the language. He's just giving you some basic guidelines to help beginners.

 

[jutfrank]

I'm not surprised everybody on both forums is confused about this. It's because you haven't given the proper context of the exercise. Let me clarify this:

The exercise is to practise using could have done and couldn't have done (not could do!). Quote Murphy (my highlighting):

Read this information about Ken:

Ken didn't do anything on Saturday evening.
Ken doesn't know anything about machines.
Ken was free on Monday afternoon.
Ken was short of money last week.
Ken's car was stolen on Monday.
Ken had to work on Friday evening.


Some people wanted Ken to do different things last week but they couldn't contact him. So he didn't do any of these things. You have to say whether he could have done or couldn't have done them.

1) Ken's aunt wanted him to drive her to the airport on Tuesday.
Answer: He couldn't have driven her to the airport (because his car had been stolen).

Etc.

The idea is that it would not have been possible for Ken to drive his aunt to the airport, even if she had been able to contact him. To repeat: could do is not correct. That is not what the exercise wants you to say.

 

[Rachel Adams]

The idea is that it would not have been possible for Ken to drive his aunt to the airport, even if she had been able to contact him. To repeat: could do is not correct. That is not what the exercise wants you to say.

But what is the difference between "could not" and "could not have done"? So "could not" is wrong in this exercise, isn't it?
I found a similar discussion. I thought in Murphy's exercise either can be used as in the situation given in the thread below.

https://www.usingenglish.com/forum/threads/204550-couldn-t-do-vs-couldn-t-have-done

https://forum.wordreference.com/threads/could-do-vs-could-have-done-past-possibility.2538125/

In 1998 I couldn't start a business though I wanted it so much. In 1999 I could have started a business, but I didn't - the desire was gone.
In 1998 I couldn't start a business though I wanted it so much.In 1999 I was able to start a buisness and I did. Now I am a famous businessman.

Post #17.

I am not arguing of course. I am just trying to understand why do some people say either "could" or "could have done" can be used.

 

[tzfujimino]

I
1. "Ken's aunt wanted him to drive her to the airport on Tuesday. He couldn't have driven her to the airport (because his car had been stolen.)"

=If Ken's aunt had asked him to drive her to the airport on Tuesday, he couldn't have driven her there.

Does that help?

 

[Rachel Adams]

=If Ken's aunt had asked him to drive her to the airport on Tuesday, he couldn't have driven her there.

Does that help?

The question is can "could" be used instead of "could have done?" Or is "could" only used when talking about past abilities and permissions?

I was judging by this discussion. That's why I thought in my original question either can be used. In this situation and in Murphy's examples the people couldn't do something. So why can't I use "could not"?

And when talking about past options, possibilities, hypothetical statements, and lost opportunities is "could have" again the only option? I provided the link for the situations I am asking about.
https://www.grammar-quizzes.com/modal5c.html

 

[tzfujimino]

Murphy's examples the people couldn't do something. So why can't I use "could not"?

As jutfrank said in #8, "The exercise is to practise using could have done and couldn't have done (not could do!)."

"Ken's aunt wanted/asked him to drive her to the airport on Tuesday, but he couldn't (drive her ...)" makes sense, and it's correct.

 

[Rachel Adams]

As jutfrank said in #8, "The exercise is to practise using could have done and couldn't have done (not could do!)."

"Ken's aunt wanted/asked him to drive her to the airport on Tuesday, but he couldn't (drive her ...)" makes sense, and it's correct.

Thank you!!!! That's what I was trying to find out. Could you please tell me if in these examples if I choose to use "could" it would be also correct? I mean for past options, possibilities, hypothetical statements, and lost opportunities.
https://www.grammar-quizzes.com/modal5c.html I copied and pasted each sentence if it's more convenient.
1. "Passengers could have taken other smaller transatlantic ships."

2. "The captain could have chosen a more southern transatlantic route."

3. "The owners could have pressed designers to include more safety flotation compartments."

4. "Watchmen could have asked the captain to slow down due to fog."

5. "The owners could have supplied more life jackets". (but they didn't)

6. "The captain could have held emergency practices."(but he didn't)

7. "The captain could have radioed other ships in the area to ask about iceberg sightings". (but he didn't)

8. "The captain could have refused help."
Maybe he did, maybe he didn't.

9. "The Titanic could have been off course, too far north."
Maybe it was, maybe it wasn't.

10."The captain of the ship Californian could have ignored the call. "
Maybe he did, maybe he didn't.

HYPOTHETICAL STATEMENT

11. "The captain could have refused to pilot the ship."
but he didn't.

12. "The captain could have held emergency practices."
but he didn't.

13. "The White Star Line could have supplied more boats."
but they didn't.

 

[tzfujimino]

I don't think "could" (instead of "could have") works in those sentences in your last post.

 

[jutfrank]

But what is the difference between "could not" and "could not have done"?

I'm going to interpret this question to mean 'What is the difference between could do and could have done?' Look:

He couldn't have driven her there. = He wouldn't have been able to drive her there.
He couldn't drive her there. = He wasn't able to drive her there.

The two forms above have different meaning. This is what you should focus on.

So "could not" is wrong in this exercise, isn't it?

Yes, could do is wrong. I thought I made that clear. Look again at the instruction and the task context. You have to choose either could have done or couldn't have done.

I found a similar discussion. I thought in Murphy's exercise either can be used as in the situation given in the thread below.

Then perhaps you should stop reading similar discussions. They re confusing you.

I am just trying to understand why do some people say either "could" or "could have done" can be used.

The main reason is this: The people who say could do is correct have not seen the context of the exercise, which means they do not understand the meaning that Raymond Murphy has in mind. The thing that you're missing is that the idea of the exercise is not to say what was not possible. The idea is to say what would have been possible or not possible. That's a different meaning. The part of the task instruction that tells you this is the information that none of the people were able to contact Ken. I'll put it one more time:

He couldn't drive his aunt to the airport. = He wasn't able to drive his aunt to the airport.

He couldn't have driven his aunt to the airport. = Even if Ken's aunt had been able to contact him, he wouldn't have been able to drive her to the airport anyway, because he didn't have his car at the time.

These have different meanings. Only the second sentence is correct and makes sense within the context of this particular exercise.

 

[Rachel Adams]

Thank you so much for taking time to write your explanation. "Could" must be the wrong option in these sentences too. "I couldn't have won, so I didn't go in for the race." From Michael Swan's textbook. My question sentence: "I couldn't win so I didn't go in for the race."

Michael Swan: "I could have won the race if I hadn't fallen." My question: "I could win the race if I didn't fall." In the examples about the Titanic "could" cannot be used either. I hope I don't misunderstand anything anymore.

 

[jutfrank]

"Could" must be the wrong option in these sentences too. "I couldn't have won, so I didn't go in for the race." From Michael Swan's textbook. My question sentence: "I couldn't win so I didn't go in for the race."

If you give me the title, edition, and page number of that book, I'll explain what Michael Swan is saying and why. Alternatively, you could transcribe exactly the whole section here.

Michael Swan: "I could have won the race if I hadn't fallen." My question: "I could win the race if I didn't fall." In the examples about the Titanic "could" cannot be used either. I hope I don't misunderstand anything anymore.

You still misunderstand. Like I said, if you can tell me the section of the book you're looking at, I'll try to explain it clearly for you. It's a very difficult grammar point.

 

[Rachel Adams]

If you give me the title, edition, and page number of that book, I'll explain what Michael Swan is saying and why. Alternatively, you could transcribe exactly the whole section here.



You still misunderstand. Like I said, if you can tell me the section of the book you're looking at, I'll try to explain it clearly for you. It's a very difficult grammar point.

It is section 7. 82 6. "Could have ..." I can't copy and paste it. I will also upload the screenshot.

1. "I could have won the race if I hadn't fallen."

2. "I couldn't have won, so I didn't go in for the race."

Can the structure of these sentences be changed and can I use "could not" and "didn't fall" in #1 and "could not and "hadn't gone" in #2? Are the sentences about the Titanic similar in post #13 and would it be wrong to use "could" instead of "could have done" in them as well as it was in Raymond Murphy's examples?
I appreciate your help! It's definitely very difficult.

The structure of Swan's sentence "I couldn't have won, so I didn't go in for the race" is similar to my sentence in one of the previous posts where only the first sentence is correct. Is there any connection between them?


1. "If he didn't say "hello", he couldn't have seen you".

2. "If he didn't say "hello", he couldn't see you."

3. "If he hadn't said "hello", he couldn't have seen you."

4. "If he hadn't said "hello", he couldn't see you."

https://www.usingenglish.com/forum/threads/288176-If-he-didn-t-say-hello-sentences

 

[jutfrank]

It is section 7. 82 6. "Could have ..." I can't copy and paste it. I will also upload the screenshot.

Thank you.

Can the structure of these sentences be changed

No. If you change the structure, you change the meaning and use. The use of could have done, as Swan says very clearly is for unrealised past ability or opportunities.

can I use "could not" and "didn't fall" in #1 and "could not and "hadn't gone" in #2?

No.

Are the sentences about the Titanic similar in post #13

Only 11, 12, 13 are—the ones labelled 'HYPOTHETICAL STATEMENT'. In the quiz that you link to, the similar sentences are the ones under the heading 'Lost opportunities'.

and would it be wrong to use "could" instead of "could have done" in them as well as it was in Raymond Murphy's examples?

Yes. It's always wrong to use could do when you mean could have done in the sense of unrealised past ability or opportunities.

The structure of Swan's sentence "I couldn't have won, so I didn't go in for the race" is similar to my sentence in one of the previous posts where only the first sentence is correct. Is there any connection between them?

I don't know which of your sentences you're referring to.

 

[Rachel Adams]

Thank you.



No. If you change the structure, you change the meaning and use. The use of could have done, as Swan says very clearly is for unrealised past ability or opportunities.



No.



Only 11, 12, 13 are—the ones labelled 'HYPOTHETICAL STATEMENT'. In the quiz that you link to, the similar sentences are the ones under the heading 'Lost opportunities'.



Yes. It's always wrong to use could do when you mean could have done in the sense of unrealised past ability or opportunities.



I don't know which of your sentences you're referring to.

I was referring to these sentences, especially to the first sentence. What is the name of this construction?
1. "If he didn't say "hello", he couldn't have seen you".

2. "If he didn't say "hello", he couldn't see you."

3. "If he hadn't said "hello", he couldn't have seen you."

4. "If he hadn't said "hello", he couldn't see you."