Will
可能，大概
用来预测，我们认为未来会发生什么。

I think it'll rain tonight.
我想今晚会下雨。

注意：如果预测“不会……”，是把 think 变成否定，will 不变 —> 
I don't think it'll rain tonight。
我想今晚不会下雨。
（不说 I think it won't rain tonight.）

I'm sure he'll be a successful lawyer one day.
我相信有一天他会成为一名成功的律师。
successful 成功的

I think it'll cost a lot of money to fix.
我想它修起来要花很多钱。
fix 动词，修理

有些预测是关于事实的——
It's all wool. 这是纯羊毛的/全毛的。
It'll shrink if you wash it in hot water.
如果用热水洗，会缩水的。
shrink 动词，缩小，变小

还有对现在的预测——
That'll be Mike at the door.
敲门的可能是迈克。