Could you please explain how to use “be + to + verb," as in the sentence below? –Elihu, Mexico
The construction “be + to + verb” is a formal construction that is used either a) to give an instruction or command, or b) to tell what is going to happen in the future.
In the following three sentences, the “be + to + verb” construction signals that these are commands. This construction makes the sentences sound serious and formal.
In the following sentences, the “be + to + verb” construction tells us that these sentences are about planned or scheduled events.
Again, these sentences sound formal. If we change the verb construction to “be + going + to + verb,” they retain the same meaning but sound less formal.
I hope this helps.