"I must / have to call her." "No, you don't have to."

[Michaelll]

As Raymond Murphy says 'must' is very similar to 'have to' (in affirmative sentences). But they're completely different in negative sentences.

(affirmative)
I think I have to call her. (= I think I must call her)
I think I must call her. (= I think I have to call her)
(negative)
You don't have to call her. (= you don't need to do it, but you can if you want)
You must not call her. (= you're obliged not to do that)

So I'd like to ask, would B's reply with must work? Or should it be the one with 'don't have to' even as a response to "I must call her"?

A: I haven't spoken to Kate for ages. I have to call her.
B: No, you don't have to. (= you don't need to do it, but you can if you want)

A: I haven't spoken to Kate for ages. I must call her.
B: No, you must not. (= you don't need to do it, but you can if you want) (?)
B: No, you don't have to. (= you don't need to do it, but you can if you want) (?)

In other words, is "No, you don't have to ..." only a response to "I have to ...", or could it also be a response you "I must ..."?

 

[Tarheel]

"You must not call her" doesn't mean you're not obliged to do so. It means DON'T DO IT!

 

[Michaelll]

"You must not call her" doesn't mean you're not obliged to do so. It means DON'T DO IT!

I meant "You're obliged not to do so", not "You're not obliged to do so".

And I wrote it this way:

(affirmative)
I think I have to call her. (= I think I must call her)
I think I must call her. (= I think I have to call her)
(negative)
You don't have to call her. (= you don't need to do it, but you can if you want)
You must not call her. (= you're obliged not to do that)

 

[5jj]

In your last question you wrote:

A: I haven't spoken to Kate for ages. I must call her.
B: No, you must not. (= you don't need to do it, but you can if you want) (?)

 

[Michaelll]

In your last question you wrote:

It was a question if I could use 'No, you must not' as a respond to "I must do that something" with the meaning of "No, you don't have to".

I explained it all in #1.

So I'd like to ask, would B's reply with must work? Or should it be the one with 'don't have to' even as a response to "I must call her"?

A: I haven't spoken to Kate for ages. I have to call her.
B: No, you don't have to. (= you don't need to do it, but you can if you want)

A: I haven't spoken to Kate for ages. I must call her.
B: No, you must not. (Would this work with the meaning of 'you don't have to' in this context?)
B: No, you don't have to. (Would this work in this context as a respond to "I must call her"?)

In other words, could "No, you don't have to ..." only be a response to "I have to ...", or could it also be a response you "I must ..."?

 

[Michaelll]

I see, I couldn't explain properly what my question was about. I'll put it another way.

Does B's reply work as well here as in the dialogue at the very bottom?
A: I haven't spoken to Kate for ages. I must call her.
B: No, you don't have to. (= you don't need to do it, but you can if you want)

A: I haven't spoken to Kate for ages. I have to call her.
B: No, you don't have to. (= you don't need to do it, but you can if you want)

 

[5jj]

That's possible.

 

[Michaelll]

That's possible.

A: I haven't spoken to Kate for ages. I must call her.
B: No, you must not.

Here B's reply would mean "Don't call her!", right?

 

[jutfrank]

A: I haven't spoken to Kate for ages. I must call her.
B: No, you must not.

Here B's reply would mean "Don't call her!", right?

Right.

However, at the risk of complicating things hugely, I think one could make an argument that in contraction (mustn't instead of must not), a zero necessity interpretation rather than a negative necessity one, could be had.

If we change the context, the case could be made better. Take the following utterance:

You mustn't worry.

Could it mean?:

a) There's no need for you to worry.
b) You need to not worry.

I think the answer is yes to both questions.



For an investigation of this point, see the link below:

https://pdfs.semanticscholar.org/66c8/819451f038423dd075252f169abb6c0fbf7a.pdf

 

[Michaelll]

So, no matter if it's "I must call her" or "I have to call her" in A's line, B still can say "No, you don't have to" as a respond (= B doesn't have to match the verb), correct?

A: I haven't spoken to Kate for ages. I have to call her.
B: No, you don't have to. (= you don't need to do it, but you can if you want)

A: I haven't spoken to Kate for ages. I must call her.
B: No, you don't have to. (= you don't need to do it, but you can if you want)

 

[jutfrank]

So, no matter if it's "I must call her" or "I have to call her" in A's line, B still can say "No, you don't have to" as a respond (= B doesn't have to match the verb), correct?

Yes. Because both must and have to express necessity and don't have to expresses zero necessity.


I'm wondering where your idea of 'matching the verb' comes from. Is this another of these 'rules' that you've been talking about?

I think we should be careful here to separate issues pertaining to basic meaning (semantics), which it seems think your line of questioning here is essentially about, and use of language, (pragmatics) in regards to whether your dialogues are illustrative of natural speech and the real-life ways that we tend to use words in context. I think your second dialogue is awful. Speaker A is probably just trying to remind herself to call Kate. It's a very bizarre response on B's part to prohibit her from doing so. For that reason, I'd say that B is an infelicitous response (i.e., wrong). I know that you've just made these examples up in a rush to try to frame your question, but you really must be careful with what models you use. As I told you before, focus either on authentic examples that have been uttered by native speakers, or ones that have been made up for you by teachers. That will make your threads shorter too, since many members here hold the idea of naturalness in language paramount, and will attempt to correct anything you say that doesn't sound like real speech or writing.

 

[Michaelll]

I'm wondering where your idea of 'matching the verb' comes from. Is this another of these 'rules' that you've been talking about?

To be honest, I simple heard this dialogue "Should I phone for a taxi for you?" "No, you shouldn't".
In that situation, it was clear that the last line meant "No, you don't have to" rather than "You should not do it! (in the usual meaning of "must not" but less strong)".

P.S. by (in the usual meaning of "must not" but less strong) I mean this: "You must not do it!" = is a strong one, "You should not do it!" is a similar thing but not as strong. So after hearing this dialogue, I came to the conclusion that "You shouldn't do it" has two meanings (depending on the context):
1. You don't have to do it.
2. You must not do it. (but not as strong)

 

[jutfrank]

To be honest, I simple heard this dialogue "Should I phone for a taxi for you?" "No, you shouldn't".
In that situation, it was clear that the last line meant "No, you don't have to" rather than "You should not do it! (in the usual meaning of "must not" but less strong)".

I see. Do you mean you heard that in your real life, or in a film or something? Was it between two native speakers? It's a very odd exchange, so we'd have to hear how the exchange played out in context to comment usefully. It seems as though the second speaker is deliberately trying to make a strange response, perhaps to be sarcastic or something. Again, let's look at authentic examples in context.

P.S. by (in the usual meaning of "must not" but less strong) I mean this: "You must not do it!" = is a strong one, "You should not do it!" is a similar thing but not as strong. So after hearing this dialogue, I came to the conclusion that "You shouldn't do it" has two meanings (depending on the context):
1. You don't have to do it.
2. You must not do it. (but not as strong)

Sorry, I don't follow this part. 'Should' is not a weaker from of 'must'. Is that what you're saying?

 

[Michaelll]

I see. Do you mean you heard that in your real life, or in a film or something? Was it between two native speakers? It's a very odd exchange, so we'd have to hear how the exchange played out in context to comment usefully. It seems as though the second speaker is deliberately trying to make a strange response, perhaps to be sarcastic or something. Again, let's look at authentic examples in context.

It was an American movie, unfortunately I forgot what the movie was. But I promise, "No, you shouldn't" is what I heard as a response.
How do you think B should have responded to "Should I get a taxi for you?"? "No, you ..."

Sorry, I don't follow this part. 'Should' is not a weaker from of 'must'. Is that what you're saying?

It's not me. It's from a Raymond Murphy's book.

 

[5jj]

How do you think B should have responded to "Should I get a cab for you?"? "No, you ..."

"Don't bother, thanks."

It's not me. It's from a Raymond Murphy's book.

Murphy said that that should is not as strong as must. He did not say that it is a weaker form of must.

My tee way, Murphy has many useful ideas, but sometimes has a tendency to over-simplify.

 

[Michaelll]

Murphy said that that should is not as strong as must. He did not say that it is a weaker form of must.

I didn't say that either, did I? Read carefully #12.

My tee way, Murphy has many useful ideas, but sometimes has a tendency to over-simplify.

Which is a very good idea of his.

 

[jutfrank]

It was an American movie, unfortunately I forgot what the movie was. But I promise, "No, you shouldn't" is what I heard as a response.
How do you think B should have responded to "Should I get a taxi for you?"? "No, you ..."

There are so many ways to answer this. I might say No, it's all right, thanks.

(The speaker here is rejecting an offer, not answering a question!)

It's not me. It's from a Raymond Murphy's book.
View attachment 5272

I see. Yes, I think you've misinterpreted what Murphy means. He's not saying that should and must have the same meaning, and that the difference is only about strength/weakness. They simply have different meanings. (Still, I think this is probably quite badly worded.)

 

[Michaelll]

I think you've misinterpreted what Murphy means.

You think I've misinterpreted what Murphy means? Well, how else could his words be interpreted except in the sense that they express?

There are so many ways to answer this. I might say No, it's all right, thanks.

"No, you shouldn't" wouldn't work at all as a polite response?

A: Should I get a taxi for you?
B: No, thanks, you shouldn't.

 

[jutfrank]

You think I've misinterpreted what Murphy means?

I think it's possible, yes. I don't quite understand the last part of your post #12.

"No, you shouldn't" wouldn't work at all as a polite response?

A: Should I get a taxi for you?
B: No, thanks, you shouldn't.

Not as a way to simply reject an offer, no.

 

[Michaelll]

I think it's possible, yes. I don't quite understand the last part of your post #12.

No.

Ok, I get it, thank you very much!

By the way, a little off-topic, is there any difference in meaning between "You need not to worry" and "You need to not worry" (from #9)?
(I understand that "You don't need to worry" is a completely different idea by analogy with "I didn't have to do it" and "I had not to do it")

You need to not worry.