Guide to English grammar

'll buy some postcards. (I'm deciding now.)
I'm going to buy some postcards. (I've already decided.)

NOTE
Will expresses a definite action in the future, not just a wish.

Action Wish

There's a shop here. I'll buy some postcards. -OK, I'll wait for you. I want to buy some postcards, but I haven't got any money.

5 Will sometimes expresses willingness.

Jim will translate it for you. He speaks Italian.
I'll sit/ I'm willing to sit on the floor. I don't mind.
Won't can express unwillingness or an emphatic refusal.
The doctor won't come at this time of night.
I won't put up with this nonsense.

NOTE
We can also use won't when the subject is not a person.

The car won't start.
This screw won't go in properly.

6 We can use I'll/we'll and will/won't you in offers, promises, etc.

Offer Promise Invitation Request

I'll hold the door open for you. - Oh, thanks. (I promise) I'll do my best to help you. Won't you sit down? Will you do something for me?

7 When we can't decide, we use shall I/we to ask for advice or suggestions.

Where shall I put these flowers? - I'll get a vase.
What shall we do this weekend?
We can also use shall I/we for an offer.
Shall I hold the door open for you? - Oh, thanks.

A practical guide to English grammar 80

8 We can use you shall for a promise.
You shall be the first to know. (I promise).
9 Will is sometimes used in formal orders. It expresses the order as a definite future action. This emphasizes the authority of the speaker.
You will leave the building immediately. Uniform will be worn.
Shall is sometimes used for formal rules.
The secretary shall give two weeks' notice of such a meeting.