The man in the room和There is a man in the room有什么区别?

the man in the room后面应该还有句子,它并不是完整的,但也可以理解为“in the room”是用来修饰"the man”的,可译为“那个在房里的男士”.
而“There is a man in the room.”语法成分则是完整的,译为“房间里有个男人.”