[i] He has to be foolish.
[ii] They all have to be Englishmen.
(From a Korean English-grammar book)

The book says both examples above are wrong, for ‘have to’ cannot be used for guessing something. But the reason itself seems to be not true, because there are its usages as below. Can the two examples above be wrong because of any other reasons? Or can both be accepted?

This has to be the worst restaurant in town. [epistemic] (CGEL, p.205)

have to: (also have got to especially in British English) used to say that something must be true or must happen.
There has to be a reason for his strange behaviour. This war has got to end soon.
(Oxford Learner's)

have to:
d — used to say that something is very likely
It has to be close to noon.
She has to be the most beautiful woman I've ever seen. [=I think she is the most beautiful woman I've ever seen]
He has to have a lot of money to live the way he does.
The bus has to be coming soon.
There has to be some mistake.
(Merriam-Webster’s Learner’s)

  • This is an interesting question, but mostly because of the word foolish.
    – user230
    Jul 20, 2014 at 7:54
  • Did the book say why those examples were wrong? Perhaps they are wrong when trying to be used in a certain way.
    – J.R.
    Jul 20, 2014 at 10:50
  • @J.R. That I said is all it says. It being very brief and summarized well, I like to consult it. This is its merit, and its weakness.
    – Listenever
    Jul 20, 2014 at 11:31

1 Answer 1


I think your Korean grammar is overstating the case. In both epistemic (inferential) and deontic/dynamic (obligation/necessity) contexts there is a preference for present-tense must over have/has to in the stuffiest sort of formal writing; but today past-tense had to is generally preferred even there, because must can be tense-ambiguous.

I must get some money. ... unambiguously means he needs money now (or in the more or less immediate future), BUT
He said that he must get some money ... leaves it ambiguous whether he needed the money then, or needs it now, or both, WHILE
He said that he had to get some money ... unambiguously means he needed the money then.

HAVE to is generally acceptable in all registers, and must be used when the modal itself is cast in the progressive or perfect construction, since must cannot support these.

TO BE ADDED: a discussion of differences between must and HAVE to with complements of various aspects.

  • I am not sure I understand your answer. Are you talking about deduction? Because if you are, your answer means that we prefer "He had to have a lot of money" over "He must have had a lot of money".
    – fluffy
    Jul 20, 2014 at 15:56
  • @fluffy Not quite. The equivalent of He must have had a lot of money is He had to have had a lot of money. But I will rewrite to address the ambiguities. here. Jul 20, 2014 at 16:51
  • @StoneyB Thank you so much. Now I can tell how the so concise and ‘overstating’ words need to be said again. I find a passage that backs your answer - “This epistemic use of [iii], This has to be the worst restaurant in town, is widely found in AmE, but is still fairly rare in BrE.”
    – Listenever
    Jul 20, 2014 at 21:31
  • @StoneyB I heard that the Korean book is very old and nowadays they don’t consult much. It’s almost first generation, this was born 1967 and General Secretary Ban Ki-moon must have read it, in English grammar publications in Korea. And it had almost copied Japanese grammar system then, they say widely, that is told strongly influenced by old British grammars. However, it’s very much concise, for that reason very useful for me.
    – Listenever
    Jul 20, 2014 at 21:31
  • 1
    Onions was in fact a notable scholar--editor of the OED, director of the Early English Text Society, and so forth. The five patterns were apparently very influential in Japan, too -- see this article. Jul 21, 2014 at 0:30

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