I believe this is not true.

[Yourjones]

Hello

I was told I should not say "I believe this is not true" when I can say "I don't believe this is true". Is this a rule that I must follow? And what is this rule called?

Thanks.

 

[Matthew Wai]

I think the definition below is a telling explanation.
'Believe
to be sure that something is true' (My emphasis.) ── quoted from http://www.ldoceonline.com/dictionary/believe

 

[TheParser]

***** NOT A TEACHER *****

Some experts say (and I believe them) that the farther away the word "not" is from the beginning of a sentence, the less harsh (rude) it sounds.

If my boss (if I were working) told me that my supervisor had said bad things about me and if I did not believe my boss (that is, I thought that he was, well, lying to me), I would definitely say, "Excuse me, sir, but I believe that is not true" instead of "No way! I don't believe that is true!" (If I did, I would probably be looking for a new job the next day.)


*****

The idea (that putting the negative toward the end of the sentence is more courteous) is shown, I believe, in these two sentences that I have made up:

"Go away! I don't have any money."
"I'm sorry, but I have no money."

 

[Tarheel]

"I believe this is not true" is perfectly fine. "I believe that is not true" is also good.)

 

[Matthew Wai]

I would definitely say, "Excuse me, sir, but I believe that is not true".

Why not say '... I think that is not true'?

 

[Yourjones]

Thanks. What if I say "I think he is not right"? Should I say "I don't think he is right"?

 

[Weaver67]

I believe there is no mistake in the OP's original sentence.
Another definition can be found here: http://www.oxforddictionaries.com/definition/english/believe.

Meaning #2 in that definition:
"2 [with clause] Hold (something) as an opinion; think"


Maybe it is not that telling but still it is no less reliable.

I am not a teacher.

 

[Yourjones]

Can't be clearer, thanks! I guess "None of my friends likes him" sounds quite similar to "All of my friends don't like him". Am I right? Any difference?

 

[Tarheel]

Why not say '... I think that is not true'?

That is good too.

 

[Tarheel]

Thanks. What if I say "I think he is not right"? Should I say "I don't think he is right"?

Those are both fine.

 

[Weaver67]

Why not say '... I think that is not true'?

Indeed, why? Why so many synonims? What are they for? Why so many ways to express one and the same general idea?
There is one possible answer to this, Matthew. And that is because, I believe , the language would be incredibly dull without them.

 

[Tarheel]

Can't be clearer, thanks! I guess "None of my friends likes him" sounds quite similar to "All of my friends don't like him". Am I right? Any difference?

Yes, there is. Stick with: "None of my friends like him."

 

[Matthew Wai]

the language would be incredibly dull without them.

And is incredibly complicated with them.

 

[emsr2d2]

Why so many synonyms?

Note the correct spelling shown above.

 

[Weaver67]

And is incredibly complicated with them.

Complicated? Maybe.
To my mind, it depends on one's take on the language. If one prefers to approach it like a mathematician would do, then yes, "complicated" is exactly the word; but I for one woud go for "challenging" instead. Still, either way, there must be a price for its expressiveness -- no one can really master the language without paying it.

Not a teacher.