A practical english grammar - Vyssaja skola 1978
Verb + Infinitive
Sound symbols
The number of characteristic verbs that can be followed by infinitives is rather large, and so we will divide our discussion of them into sections. First, we will discuss a number of extremely important idioms involving verbs and infinitives whose meaning seems to overlap in many cases with that of the modals. The remainder will be grouped around meaning categories.
BE TO. This idiom is used only with these forms of be: am, is, are, was, were. No compound forms of be arc ever used, nor can be itself be nonfinite. It expresses actions that are arranged, ordered, scheduled to happen in some practical way.
You are to complete this work by tomorrow.
You were to arrive earlier, but we were delayed on the road. Where is the child that is to be examined?
BE GOING TO. This idiom is so important, and so frequent in its occurrence, that many grammarians consider it one of the “tenses” of the English verb. It expresses an event in the future that is assumed (by the speaker) to be fairly certain of occurrence. In the past tense, it usually names events that were expected to happen, but did not.
It’s going to rain this afternoon.
Are they going to call you before they leave?
She looks as though she’s going to faint.
Even though this idiom is called “future,” like the verb phrase with the modal will, the two are by no means interchangeable. Be going to expresses a great deal more certainty or definiteness of intention than will docs.
We’ll see them when we get to New York (a simple statement).
We’re going to see them when we get to New York (surely; definite plans have been made).
BE ABOUT TO. This idiom means that a later event is not only expected but is imminent or threatened (but there may be still time to prevent it).
That tree was damaged by the storm and is about to fall. We’re about to start the lesson; you arrived just in time.
This expression is not often used in the negative; when it is so used, it is an emphatic way of saying that the subject is (was) adamantly determined that the event named by the second verb will not happen. In the negative, the strong stress is always on about.
Ile’s not about to sell his horse. (He is very fond of the horse, and under no circumstances would he agree to sell it.)
HAVE TO. This idiom is almost identical in its meaning with must, and in fact replaces must in those places where must can not serve. Must has no past tense, for instance, and so have to is used to express past necessity, except sometimes in subordinate clauses (see Chapter 8); also, since must not means “prohibition” and not “absence of necessity,” the latter meaning is expressed by not have to.
We had to look all over town before we found what we wanted.
You don’t have to make me another copy of that report, Miss Martin; this copy will be quite satisfactory.
Have got to means the same thing as have to (in the present tense only in American English; British had got to = American had to). The only reason for choosing one or the other seems to be a puristic hesitation to use the verb get. See the note on this subject at the end of this chapter.
BE ABLE TO. In many ways this expression is a substitute for the modal can. Since can has no inflections, other than could for the past tense—and the meaning of could is ambiguous—be able to is used whenever the sentence requires an inflection.
I’m glad to be able to help you. (Can can not follow to.)
We weren’t able to find it. (Could is ambiguous; it may mean past, but it also means contemporary unreality.)
I have never been able to understand trigonometry. (Can can not be used in present perfect phrases.)
BE SUPPOSED TO. This idiom (usually pronounced /sapowstuw/) expresses a mild compulsion or obligation, similar in meaning to ought to and must, but not as strong.
A meal is supposed to start with soup, not dessert.
We’re not supposed to wear hats in school.
USED TO. This expression is always past tense. It specifies events that were habitual or characteristic of the past, and it usually has the added meaning that the event formerly occurred but no longer does.
The pronunciation of used to is /yuwstuw/. The negative is didn’t use to /yuwstuw/ for most American speakers; some British speakers say used not to /yuwzd nat tuw/ or even usedn’t to /yuwsənt tuw/. The interrogative uses did, and did is the echo.
Do the Whites still live on Elm Street?
No; they used to live there, but they moved away last year.
I used to go swimming a lot when we lived near the coast. Didn’t you use to go to that school?
He used to be your teacher, didn’t he?