那男孩高兴地跳个不停。
d.表示两个动作是同一动作
He who helps others is helping himself.
帮人就是帮自己。
If you insist on doing it, you are doing a foolish thing.
如果你坚持做这件事,你就是在干傻事。
e.be动词的进行时态
be动词一般不用于进行时态。但有时可用“am, is, are + being +形容词”结构表示暂时或故意如此。
The boy is being naughty.这孩子有点儿淘气。
I don't think you are being fair.
我认为你不公平。
He is being modest.
他现在很谦虚。
比较:
You are not polite.
你不讲礼貌。(一贯如此)
You are not being polite.
你可有点儿不礼貌了。(暂时的现象)
3.不用进行时态的动词
①表示状态的动词
这类动词有seem, look, appear, have, belong to, own, hold等。
This backpack belongs to me.
这背包是我的。
He seems rather angry with you.
看起来他很生你的气。
②表示知道、信念、理解、推测、怀疑、希望等含义的动词
这类动词有know, remember, understand, see, think, believe, suppose, hope, doubt