must have known vs. had to known

[CarloSsS]

Is there any difference between the to sentences below? There is not other context provided. They're from an entrance test to one Czech university (that is, not composed by natives).

He asked me for money although he had to know I would be angry with him.
He asked me for money although he must have known I would be angry with him.

I don't see much of a difference, but the answer key says that the former is correct.

 

[Rover_KE]

I don't see any difference.

Rover

 

[bhaisahab]

Is there any difference between the to sentences below? There is not other context provided. They're from an entrance test to one Czech university (that is, not composed by natives).

He asked me for money although he had to know I would be angry with him.
He asked me for money although he must have known I would be angry with him.

I don't see much of a difference, but the answer key says that the former is correct.

Both are possible. If anything, I prefer the second.

 

[Raymott]

I also prefer the second. But if the first had read "he had to have known", that would be as good.

Consider a different verb - 'do' not 'know'.
1. "He was the only one in the room - he must have done it."
2. "He was the only one in the room - he had to have done it."
3. "He was the only one in the room - he had to do it."
1 and 2 mean (roughly) the same. 3 doesn't.

 

[CarloSsS]

I also prefer the second. But if the first has read "he had to have known", that would be as good.

Consider a different verb - 'do' not 'know'.
1. "He was the only one in the room - he must have done it."
2. "He was the only one in the room - he had to have done it."
3. "He was the only one in the room - he had to do it."
1 and 2 mean (roughly) the same. 3 doesn't.

I guess the difference between 1 and 2 is that the former means something like "he did it because he wanted to", while the latter means ("somebody else wanted him to do it, so he did it"). Right? However, I read in Swan's PEU (361.1 - the last paragraph), that in AmE, "must" can be replaced with "have to" with no difference in meaning:

"I really have to stop smoking" is the same (in AmE) as "I really must stop smoking".

Having said that, can the first and second sentence mean the same? Not just roughly the same? Similarly as the two sentences that I gave in the first post mean the same?

 

[bhaisahab]

I guess the difference between 1 and 2 is that the former means something like "he did it because he wanted to", while the latter means ("somebody else wanted him to do it, so he did it"). Right? However, I read in Swan's PEU (361.1 - the last paragraph), that in AmE, "must" can be replaced with "have to" with no difference in meaning:

"I really have to stop smoking" is the same (in AmE) as "I really must stop smoking".

Having said that, can the first and second sentence mean the same? Not just roughly the same? Similarly as the two sentences that I gave in the first post mean the same?

I don't see any difference in meaning.

 

[CarloSsS]

I don't see any difference in meaning.

Between these two?

1. "He was the only one in the room - he must have done it."
2. "He was the only one in the room - he had to have done it."

 

[bhaisahab]

Between these two?

Yes, between those two.

 

[CarloSsS]

What about these two? Is there any difference in meaning?

He asked me for money although he had to have known I would be angry with him. (he very likely knew before he asked me?)
He asked me for money although he had to know I would be angry with him. (he very likely knew before or after he asked me?)

 

[bhaisahab]

What about these two? Is there any difference in meaning?

He asked me for money although he had to have known I would be angry with him. (he very likely knew before he asked me?)
He asked me for money although he had to know I would be angry with him. (he very likely knew before or after he asked me?)

No, not that I can see.

 

[Raymott]

[SUP]In general, "He must have <verbed> it" means something closer to "He has/ had to have <verbed> it" than"He had to <verb> it".

But the context, as well as the actual verb will add different connotations to the meaning.

[/SUP]

 

[tzfujimino]

Hello.:-D
Please allow me to ask a question here.

"He asked me for money although he had to have known I would be angry with him."
"He asked me for money although he had to know I would be angry with him. "

Are both used to express 'certainty' about the past?
(I know 'must have + past participle' is. I thought 'had to...' is only used to talk about the past obligation.)

P.S. Raymott, your post is barely readable (because of the font size).:-D

 

[Raymott]

Hello.:-D
Please allow me to ask a question here.

"He asked me for money although he had to have known I would be angry with him."
"He asked me for money although he had to know I would be angry with him. "

Are both used to express 'certainty' about the past?
They both refer to certainty.


(I know 'must have + past participle' is. I thought 'had to...' is only used to talk about the past obligation.)
Well, as I said, I would have said “had to have known”. ‘Had to know’ refers here to certainty (even though it’s not expressed well) because it can’t mean anything else. From the context, it can’t mean “He was obliged to know”.
What do you think of it? Could it possibly mean "He was obliged to know that I would be angry with him"?

P.S. Raymott, your post is barely readable (because of the font size).:-D
Really? Is that happening a lot?

As I was trying to say above, the context is important.
The context doesn't allow for it to mean "obligation". Therefore it means "certainty".