NOT A TEACHER
(1) I found a somewhat similar sentence in Descriptive English Grammar by Professors House and Harman:
The group is to assemble at dawn.
(a) The professors explain that it indicates futurity and intention.
(i) I think that the same applies to your sentence:
(a) He will visit them tomorrow.'
(b) It is his intention (plan) to visit them tomorrow.
(2) Grammatically speaking, the two professors explain that such sentences are
examples of complementary infinitives. (You may wish to check your books for
more information on this matter.)
(3) Here is one more of their examples:
I am + to leave at noon. = I shall/will leave at noon.
(4) And here is an example from A Grammar of Present-Day English by Professors Pence and Emery:
You are + to leave in an hour.
That sounds to me something like an order. What do you think? For example, I think that they like to use this kind of sentence in the army: You are to report immediately to headquarters!
- For Teachers