there is / there are

我们常用 there be 表示某人某物的存在。

单数用 there is （日常口语there's)

复数用 there are

There is a book on your desk. 

你的桌子上有一本书。

[非正式口语] There's a book on your desk. 

There are three books on your desk. 

你的桌子上有三本书。

There are some people in the shop.

商店里有一些人。

There is a new cafe next to the school.

学校旁边新开了一家咖啡馆。

chance 机会，可能性

There is/There's no chance. 

没有可能。没有机会。

There is/There's no chance he will change his mind.

他不可能改变主意。

过去时

单数 there was

复数 there were

There was a book on your desk.

[过去的某个时间点] 你的桌子上有一本书。