There be+主语（人或物名词）+地点There is + 名词单数或者不可数名词There are + 名词复数
There be 句型表示“存在…”“有”，强调某处有某物。其中be动词有时态和单复数变化。
  
tree
cat
There is a cat under the tree.
There are three birds in the tree.
birds