用 will 来说将来的事。所有人称形式都一样：will + 动词原形（不加 -s）。口语里常缩写成 'll（I'll、she'll）。两个常见用法：预测（你觉得会发生的事）和承诺或当场决定（你要做的事）。
will + verb
I will call you tomorrow. (a promise)
It will be sunny today. (a prediction)
She'll help you with your bags.
They will arrive at six.
Not "She wills come tomorrow." — say "She will come tomorrow.". will 永远不加 -s，后面的动词保持原形（不加 "to"）。
试一试: Look at the sky. I think it ___ later. (will rain / will rains / rains) 答案: will rain — 预测将来的事，用 will + 动词原形：it will rain。"will rains" 多加了一个 -s，而 "rains" 说的是现在，不是将来。
won't = will not
要说 will 的否定，用 won't + 动词原形。（won't = will not。）所有人都一样，不用加 -s。用它来说某件事不会发生（一种预测），或者说你不会去做某件事（一种承诺）。
I won't be late, I promise. (a promise)
Don't worry, it won't rain. (a prediction)
She won't come to the party.
Not "I don't will be late." — say "I won't be late.". will 的否定形式是 won't，绝不是 “don't will”。
试一试: Don't worry, I ___ tell anyone your secret. (won't / don't will / willn't) 答案: won't — will 的否定形式是 won't + 动词原形：I won't tell.（我不会说的。）“Don't will” 和 “willn't” 都不是正确的形式，只有 won't 这一个词才对。
Will you ...?
要问将来的事，或者请别人做什么，就用 Will + 这个人 + 动词原形开头：Will you ...?
Will you be at the meeting tomorrow?
Will you help me with this box?
Will they arrive on time?
试一试: ___ you be home this evening? (Will / Do / Are) 答案: Will — 问将来的事，用 Will 开头：Will you be home?（你会在家吗？）“Do you be” 不是正确的形式，“Are you be” 又把 be 动词重复用了两次。
综合运用
现在把三种用法放在一起：肯定用 will + 动词原形，否定用 won't + 动词原形，提问用 Will you ...? will/won't 后面的动词永远是原形。
I will call, but I won't be late.
Will you help me? Yes, I will.
It won't rain, so we will go out.
试一试: ___ you call me later? Don't worry, I ___ forget. (Will … won't / Do … don't will / Will … willn't) 答案: Will … won't — 要提问，用 Will 开头：Will you call me?（你会打给我吗？）要说否定，用 won't：I won't forget.（我不会忘的。）提问用 Will，否定用 won't。