可以作為助動詞，或者系動詞。1、Beauty is an attitude. It has nothing to do with age. 美是一種態度，與年齡無關。2.The best thing to do when entering unknown territory is smile. 踏入未知地帶最好的對策就是微笑。3.A miracle is something that seems impossible but happens anyway. 奇蹟就是看似不可能，卻發生了。

1.This is what we support. 這是我們所擁護的。

2.I agree that she is the ablest of us. 我承認她是我們之中最能幹的一個。

3.This is all I have. 這就是我的全部家當。

4.This is my fault. 這是我的過錯。

5.That is mere talk. 那隻不過是空論。

6.Whatever is worth doing at all is worth doing well. 任何一件值得做的事都應該把它做好。

7.This is one of the mistakes. 這是其中的一個錯誤。

8.He is the man of all others for the job. 他是所有人之中最適於幹這工作的人。

9.This is what I gathered from his speech. 這是我從他說的話中推斷出來的。

10.What is to become of me if you go away? 如果你走的話，我的結果將是怎樣呢?

11.You should pal up with him. He is the man to be trusted. 你應該和他交朋友，他是一個可以信賴的人。

12.This is my pen. 這是我的鋼筆。

13.What! Is that true? 啊!那是真的嗎？

14.She is the youngest of us three. 她是我們三人中間最年輕的。

15.I calculate he is wrong in saying that. 我認為他說的那句話是錯誤的。