"Be Supposed To" and "Be To"

A. Be Supposed To

            Idiomatic and passive, "be supposed to" shows expectation. Someone expects you to do something in the present or the future.

1.      “Be supposed to” can be used to mean 'it is said/believed'.

Example :

• The new James Bond movie is supposed to be excellent.
• He is supposed to have been rude to Mark but I don't believe it.
• It is supposed to be the best restaurant in town.

2.      “Be supposed to” can also be used to talk about what is arranged, intended or expected. It is a bit like 'should'.

Example :

• I'm supposed to get to work by 8.
• John is supposed to turn off all the lights when he leaves.
• I'm supposed to pay my rent on the first of the month.

3.      Often there is a suggestion that the action 'supposed to' happen does not actually happen.

Example :

• I'm supposed to be there before 8 but I'm often late.
• You were supposed to phone me.
• I'm supposed to be getting on a plane to Tokyo at this very minute.

4.      'Not supposed to' often suggests that something is not allowed or prohibited.

Example :

• You're not supposed to smoke in here.
• I'm not supposed to tell you.
• We're not supposed to use the Internet for personal reasons at work.

5.      'Suppose' can also be used as a conjunction to mean 'what if'. Notice that the verb which follows it is sometimes, but not always, put 'more in the past'.

Example :

• Suppose we take the earlier train to Munich? It would give us more time there.
• Suppose we took the plane instead? That would give us even more time.
• There's nobody in reception to let our visitors in. Suppose I sit there until somebody comes?
• I'm going to ask him for a pay increase. ~ Suppose he said 'no'? What would you do?

B. Be To

1.     

S + Be + To + Infinitive V. + O / C

We use be to + infinitive when discussing formal or official arrangements or to give formal instructions or orders and your examples illustrate these aspects very well.

Example :

• The Prime Minister is to make a further visit to Devon next week.

• We are to receive a pay rise in line with inflation in September.

2.     

S + Be + To + Infinitive V. + O / C

The be to + infinitive structure is also frequently used in newspaper, radio and television reports to refer to future events. It expresses near certainty that what is forecast will happen.

Example :

• A man is to appear in court later this morning charged with the murder of the footballer, Darren Gough.
• Work is to begin this week on the new bridge across the Nile north of Aswan.

3.     

If + S + Be + To + Infinitive V. + O / C

We often use be to + infinitive in the if-clause in conditional sentences when talking about preconditions for something to happen.

Example :

• If we are to catch that train, we shall have to leave now.

4.     

S + Be + To + Be + V3 + O / C

Be to + passive infinitive is often used when giving instructions. It is noticeable always on medicine bottles and can be seen on other official notices too.

Example :

• These benches are to be removed from the changing rooms.

5.      Note that although this structure is used to talk about current and future arrangements and events, it is configurated in present and past tenses - see the above examples. However, be to + perfect infinitive is sometimes used to show that a planned event did not materialise.

Example :

• He was to have appeared in the West End show but broke his collar bone during rehearsals.

• They were to have picked strawberries this morning, but the torrential overnight rain made the field too muddy.