A practical english grammar - Vyssaja skola 1978

Use of FOR as marker of the subject of an infinitive
Sound symbols

We have seen how an infinitive, with its preceding noun subject, can directly follow certain verbs. When these two structures, which we shall call an infinitive phrase, are used in other ways, the function word for occurs before the subject of the infinitive.

Infinitive phrases introduced by for are used:

After the complements of linking verbs (Pattern 9.1).

With dummy subject IT:

It is easy for you to do that.

It was important for eyeryone to be fully informed.

It’s unusual for there to be so much rain.

With personal subjects:

We are eager for you to meet him.

She seemed ashamed for us to see her house in disorder.

As modifiers of nouns.

I have orders for you to return at once.

Our wish for him to succeed is more important than any other consideration.

It’s a shame for you to be troubled this way.

As a sentence modifier, to express purpose.

For us to arrive on time, we have to leave at once.

This type of phrase usually occurs at the beginning of the sentence. When it occurs elsewhere, in order is put before it.

I turned up the volume, in order for everyone to hear better.

Two-word verbs including FOR. Some two-word verbs that include for can be followed by infinitive phrases:

She arranged for her daughter to meet us.

I am waiting for Mr. Sharp to come back.

In winter, we long for summer to come.