Page 113 - Practical English Usage 3ed - Michael Swan, Oxford

4 orders: You are to do your homework
The sttucture is used to give orders, often by parents speaking to children. You are to do your homework before you watch nr.
She can go to the party, but she's not to be back late.
S be + passive infinitive: It ;s not to be removed
Be + passive infinitive is often used in notices and instructions.
am/are/is (not) to be + past participle
This cover is not to be removed.
Sometimes only the passive infinitive is used.
To be taken three times a day after meals. (on a medicine bottle)
Some other common expressions with be + passive infinitive:
There's nothing to be done. She was nowhere to be found. I looked out of the window, but there was nothing to be seen.
6 tenses
Note that this structure exists only in present and past tenses. We cannot say that somebody htl3 heel! t6 g6 somewhere, or willlntttSl be t6 gB somewhere. Participle sttuctures (being t6 go) are not possible either.
For other ways of talking about the future, see 211-221.
92 be and have
1 physical conditions: hunger, thirst etc
To talk about experiencing hunger, thirst, heat, cold and certain other common physical conditions, we normally use be (or feel) + adjective, not have + noun. Note the following expressions:
be hungry (NOT htitle hltrtgeF) be thirsty be warm
be hot be cold be sleepy
Note also:
be right be wrong be lucky
be afraid
2 age, height, weight, size and colour
Be is also used to talk about age, height. length. weight, size. shape and colour. I'm nearly thirty. (NOT " htitle netlNy tt'iirfy.)
She is nearly my age.
I wish I was ten kilos lighter.
The room is ten metres long.
She is the same height as her father.
He is six feet tall.
What size are your shoes? What colour are his eyes?
Be heavy is not usually used in measuring expressions. It weighs 37 kilos. (NOT N's 37 kil6s hetltry.)
For have in expressions like have a bath, have a drink, have a walk, see 236.
be and have 92
page 81