We find to be to + infinitive to discuss official arrangements, orders or official instructions.
This structure has both active form and passive form.
The structure is:
Subject + to be to + infinitive + …
- The soldiers are to cross the border.
- We are to travel by car from Ankara to Budapest.
- Students are to take the red flag and bring it here.
We use to be to + infinitive in:
- Sentences that contain definite plans;
- Sentences that contain formal plans.
NOTE: We use this structure in formal sentences.