58 Be To + Infinitive: Passive

We use be to + infinitive when we discuss official arrangements, orders or official instructions.

We also use it when we are expecting something to happen (for Pre-conditions). Be to + infinitive can be used in the Passive form when we want to focus on the agent or when we give orders.

We use be to + infinitive if we are highlighting the agent or ‘doer’ or if we want to give orders. It is not so common to use this structure to give command/order.

• Everyone is to be fined who drive without license.
• Tents are not to be changed without permission.
• Pilot is to be helped by cabin crew.

Teachers and parents mostly use to be + infinitive when they give order to children. It is also used for official arrangements.