I am an English teacher in Türkiye. For a period of time I have been looking for some special use of some structures or words. One of them is "be to". I have read a lot but no exact explanation is acquired. For example; there are different explanations when it is used in conditionals. If you help me about the fully explanation of "be to" I'll be glad.

Best regards

Aykut Yıldırım
Hi Aykut.

Welcome to the Forum.

The best thing is if you give us some sample sentences showing the kind of thing you have qusetions about. That will help us see what exactly you are unclear about.

So, please write again.

I'm not sure what sort of explanation you are looking for.
Nevertheless, quite simply, 90% of the time you can think of "be to" as a reduction of "be supposed to" or "be expected to".

We are to begin the procedure by midnight.
= We are [supposed / expected] to begin the procedure by midnight.

Students: Are you brave enough to let our tutors analyse your pronunciation?
The structures is common in if-clauses, when the main clause expresses a pre-condition - something that must happen first if something else is to happen.

If we are to get there by luchtime we had better hurry.

he knew he would have to work hard if he wa to pass his exam.

For further information, please consult Practical English Usage (by Michael Swan, Oxford University Press 2005).
 CalifJim's reply was promoted to an answer.
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