'Have to' used for expressing certainty

[mafto]

Hiya, could you please tell me if we can use 'have to' to express certainty about something? The same way as we use 'must'.

Eg. He didn't come today, he must be ill.
Could it also be 'He has to be ill'?

Sorry if it's a silly question but I can't google it out or find it in any book and I need to know it

Thanks

 

[BobSmith]

[not a teacher]

This sounds perfect to me.

 

[bhaisahab]

I find "He has to be ill" less natural than "He must be ill" in that context.

 

[5jj]

I find "He has to be ill" less natural than "He must be ill" in that context.

I agree. I also feel that ''has to" is less confident than "must", but this may be a feeling shared by nobody else. :-?

 

[BobSmith]

I find "He has to be ill" less natural than "He must be ill" in that context.

It may be an AmE thing, but "He didn't come today, he has to be ill." sounds just as natural as "must be ill". I can easily imagine hearing "He didn't come today, he has to be ill, I just know it!" I agree that it may be less confident, but only slightly less confident.

 

[spindoctorjimbo]

Fun and crazy English is everywhere. One way to think about the real issue here is in the use of the ever-so-useful verb, "to have." Leaving aside its powerful usage in stretching out time in the 'perfect tenses,' its meaning of ownership is one that people use constantly: "I have a pain; I have an idea; I have a problem."

The use is always transitive. A direct object is required. Even the response, "I have!" to a question like, "Who has a sandwich today?" implies the direct object that the question is inquiring about.

And of course every direct object has to be a noun. This is one of those places where the flexibility of English phrasing is pretty cool and also pretty weird. Infinitives are the 'perfect' form of a verb, but they can never, ever be a verb in a sentence. Instead they are, much more often than not, phrases that do the work of a noun. "To fight is dangerous; to die today would be horrible; to play with friends is fantastic."

That is always what is happening in sentences like "he has to be sick," or in complete thoughts like "every direct object has to be a noun." Perhaps some time in the past, English users thought of their infinitives more clearly as nouns.

Perhaps sometime in the future, some grammarian will say, "We'll just call 'has to' a phrasal verb." If that ever happens, trouble will follow. How can your direct object be a verb phrase?

 

[5jj]

One way to think about the real issue here is in the use of the ever-so-useful verb, "to have."
'Have and 'Have to' are generally treated as different verbs.

And of course every direct object has to be a noun.
No, it can be, for example, a pronoun or a gerund.

This is one of those places where the flexibility of English phrasing is pretty cool and also pretty weird. Infinitives are the 'perfect' form of a verb, but they can never, ever be a verb in a sentence.
Infinitives are non-finite parts of the verb.

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