1．There be和have都可作“有”讲，但have／has作“有”讲时，表示所属关系，即“持有、占有”，而there be结构表示客观上的存在，不说明所有关系。例如：
There are two new pens in Tom's pencil-box．（强调钢笔的位置）
Tom has two new pens．（钢笔是汤姆的）
2．当主语是物或时间名词，而且表示整体与局部的关系时，there be结构与have可以互换。例如：
（1）一周有七天。
A week has seven days．
There are seven days in a week．
（2）这幢楼有20个房间。
The building has twenty rooms．
There are twenty rooms in the building．
3．在一般时态里，there不能和have（has）连用。例如：
（1）那间房子有两个窗和一个门。
【误】There have two windows and a door in the room．
【正】There are two windows and a door in the room．
【正】The room has two windows and a door．
（2）明天下午将有一次班会。
【误】There will have a class meeting tomorrow afternoon．
【正】There will be a class meeting tomorrow afternoon．
