there be+名词+现在分词
现在分词表示主动关系，同时表示动作正在进行：
There is someone waiting for him. 有人在等他。
There was a man standing in front of me. 我前面站着一个男人。
There were some children swimming in the river. 有些小孩在河里游泳。
There were a group of young people working in the fields. 有一群青年在地里劳动。
有时现在分词可表示一种状态：
There’s a piano standing against the wall. 靠墙有一架钢琴。
There’re a lot of difficulties facing us. 我们面前有很多困难。
There is a door leading to the garden. 有一座门通往花园。
有个别现在分词用于该结构时可以表示将来(正如它们可用进行时表示将来一样)：
There are ten people coming to dinner. 有10个人来吃晚饭。