Willingness: will, can
Announcing decisions: I’ll answer it.
We often use will when we tell people about a decision as we make it, for instance if we are agreeing to do something.
- OK. I’ll buy the tickets. You can buy supper after the show.
- ‘The phone’s ringing.’ ‘I’ll answer it’ . (not
I’m going to answer it.) - ‘Remember to phone Joe, won’t you?’ ‘Yes, I will.’
Note that the simple present is not normally used to announce decisions.
- I think I’ll go to bed. (not
I think I go to bed.) - ‘There’s the doorbell.’ ‘I’ll go.’ (not
… I go.)
To announce decisions that have already been made, we generally prefer going to … or the present progressive ( (see here).
- Well, we’ve agreed on a price, and I’m going to buy it.
- I’ve made my decision and I’m sticking to it.
Stressed will can express determination.
- I will stop smoking! I really will!
Refusals: I won’t do it!
Will not or won’t is used to refuse, or to talk about refusals.
- I don’t care what you say – I won’t do it!
- The car won’t start.
Promises and threats: I’ll phone you tonight.
We often use will/’ll in promises and threats. Note that the simple present is not possible in these cases.
- I promise I won’t smoke again. (not
I promise I don’t smoke …) - I’ll phone you tonight. (not
I phone …) - I’ll hit you if you do that again.
- You’ll suffer for this!
Shall is also possible in British English after I and we, but it is much less common than will.
- I shall give you a teddy bear for your birthday.
In older English, shall was often used with second- and third-person subjects in promises and threats. This is now very unusual.
- You shall have all you wish for.
- He shall regret this.
Offers: Can I carry your bag?
We often use can when we offer to do things for people.
- ‘Can I carry your bag?’ (= Would you like me to …) ‘Oh, thank you.’
- ‘I can babysit for you this evening if you like.’ ‘No, it’s all right, thanks.’
Could is possible if we want an offer to sound less definite.
- I could fix your bicycle for you, if that would help.