Page 220 - Practical English Usage 3ed - Michael Swan, Oxford

3 conditional use
WilYshali is often used to express conditional ideas, when we say what will happen if something else happens.
He'll have an accident if he goes on driving like that. If the weather's fine, we'll have the party in the garden. Look out - you'll fall! (If you're not more careful.)
Come out for a drink. - No, I'll miss the film on 1V ifI do. Don't leave me. I'll cry!
4 future events already decided: will not used
When future events are already decided, or when we can 'see them coming', we often prefer a present form (usually present progressive or going to ...).
I'm seeing the headmaster on Monday. My sister's going to have a baby. For details, see 213, 214 and 216.
5 not used in subordinate clauses: when I arrive
In subordinate clauses, we usually use present tenses instead of wiLYshali (see 580.2).
I'll phone you when I arrive. (NOT •.• when ,T will affive.) For exceptions, see 580.4,8, 260.
6 other uses of will and shall
Will and shall are not only used to give and ask for information about the future. They can also be used to express 'interpersonal' meanings such as requests, offers, orders, threats and promises. For details, see 217.
Shall I open a window? I'll break his neck! Will you get here at nine tomorrow, please?
For information about all uses of lViii, see 629.
213 future (3): going to • • •
1 a present tense
This structure is really a present tense (the present progressive of go).
We use it to talk about future actions and events that have some present reality. If we say that something in the future is going to happen, it is usually already pIarmed or decided, or it is starting to happen, or we can see it coming now. The structure is very common in an informal style. especially in speech (because conversation is often about future actions and events of this kind).
2 plans: We're going to get a new car
We use be going + infinitive to talk about plans, especially in an informal style. This structure often emphasises the idea of intention, or a decision that has already been made.
future (3): going to ... 213
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