There have been many changes in this place. 这句中为什么用have?主语是什

There have been many changes in this place.这是一个倒装句
正常语序是Many changes have been there in this place.
There be 句型本身是一个倒装,主语是复数,谓语当然用复数have了
There is a car.正常语序是a car is there.
主语many changes .谓语have been 副词做状语There ,地点状语in this place
.