试一试: Lani: I can't open this box. Diego: ___ do it for you. 补全 Diego 说的话。 (I'll / He'll / They'll) 答案: I'll — 主动帮忙的是 Diego，所以说的是他自己：I'll。说 "He'll" 或 "They'll"，就变成了别人，而不是正在说话的人。
I'll have tea（当场决定）
在说话这一刻才做的决定，而不是之前就定好的，就用 I'll + 动词原形。
I'm thirsty. I'll have some water.
Okay, I'll take the bus.
I'll call you later.
Not "I'm thirsty. I have some water." — say "I'm thirsty. I'll have some water.". 你是边说边决定的，所以用 I'll + 动词原形。
试一试: Sofia: Are you hungry? Farid: Yes. ___ a sandwich. 补全 Farid 说的话。 (I'll make / I make / I making) 答案: I'll make — Farid 是边说边做决定，当场做的决定用 'll。不加 will 的说法说的是他平常做的事。
It'll rain（预测）
用 'll + 动词原形，说你觉得会发生的事。（it'll = it will；they'll = they will。）
I think it'll rain tomorrow.
Don't worry. It'll be fine.
They'll be happy.
试一试: Wei: The wind is very cold today. Amina: ___ snow tonight. 补全 Amina 说的话。 (It'll / I'll / We'll) 答案: It'll — Amina 是在说她觉得会发生什么，说天气时我们用 It。说 "I'll" 或 "We'll"，就变成在说人了。
Not "She wills come." — say "She'll come.". 即使主语是 she，也还是 will（'ll），绝不是 wills。
试一试: Yasmin: These boxes are heavy. Mei: Hiroshi ___ help you. 补全 Mei 说的话。 (will / wills / will to) 答案: will — Will 永远不变，就算主语是 Hiroshi 也一样——没有 "wills" 这种说法。
动词保持原形
will（'ll）后面的动词保持原形。不加 -s，也不加 -ing。
He'll come at six.
She'll help you.
It'll rain later.
Not "It will rains." — say "It will rain.". will 后面用动词原形：rain，不是 rains。
试一试: Camila: Is Mei coming? Lars: Yes, she ___ the bus at eight. 补全 Lars 说的话。 (will take / will takes / will taking) 答案: will take — will 后面的动词保持原形，就算主语是 she 也一样——不是 takes，也不是 taking。
will 后面不加 to
will 后面不要加 to。要说 I'll help，不说 "I'll to help"。
I'll help you.
She'll call later.
We'll wait here.
试一试: Matilda: The window is open and it is cold. Mateo: I ___ it. 补全 Mateo 说的话。 (will close / will to close / will closing) 答案: will close — will 和动词之间什么都不加——不加 to，也不加 -ing。
Won't（否定）
要说否定，就用 won't + 动词原形。（won't = will not。）
Don't worry. I won't be late.
She won't come today.
They won't forget.
Not "I don't be late." — say "I won't be late.". 说以后不会做某事，用 won't，不用 don't。
试一试: Yasmin: Please don't tell Lars. Ethan: OK, I ___ say anything. 补全 Ethan 说的话。 (won't / don't / will) 答案: won't — Ethan 是在对接下来的事做保证，而 will 的否定是 won't。有一个选项说的是现在，另一个意思正好跟他想说的相反。
Will you...?（提问）
要提问，就把 Will 放在前面：Will you help me? 简短回答：Yes, I will. / No, I won't.
Will you help me?
Will you open the door?
Will she come? — Yes, she will.
试一试: Hiroshi: ___ you write to me from Senfarren next week? Liam: Of course I will. 补全 Hiroshi 的问题。 (Will / Did / Do) 答案: Will — Hiroshi 是在请 Liam 以后做一件事，Liam 也答应了——所以问句以 Will 开头。有一个选项问的是过去，另一个问的是他平常做的事。
用起来
把它们放在一起：主动帮忙、当场决定，或者说你觉得会发生的事，都用 'll。说否定用 won't。提问用 Will you...?
I'll answer the phone.
It'll be cold tonight.
Will you wait for me?
试一试: Lani: Are you ready for the test? Wei: Yes. It ___ be hard. 补全 Wei 说的话。 (won't / doesn't / not will) 答案: won't — Wei 说的是他对一场还没考的考试的看法，而 will 的否定是 won't。"Doesn't be" 不是英语，"not will" 把词的顺序弄反了。