[Grammar] To be [plus] verb

[shahin_67]

Hi,

I have no clear idea of what structures such as I am to buy something or she was to remain here tend to mean. Would someone please explain and compare them with structures to be going to and would/will.

Thanks in advance

 

[Chicken Sandwich]

NOT A TEACHER

See #3 http://www.ldoceonline.com/dictionary/be_1.

be to do something formal a) used to talk about arrangements for the future : Audrey and Jimmy are to be married in June.
Two men are to appear in court on charges of armed robbery.

b) used to give an order or to tell someone about a rule : You are to wait here in this room until I return.
All staff are to wear uniforms.

c) used to say or ask what someone should do or what should happen : What am I to tell her?
He is not to be blamed.

d) used to ask how something can be done : How are we to get out of the present mess?

 

[5jj]

Please credit your source, CS.

 

[Chicken Sandwich]

Please credit your source, CS.

I did credit my source in post #2.

"See #3 be - Definition from Longman English Dictionary Online."