帮我分析一下句子结构There are five students in our band.

这是一个倒装句,主语five students 谓语are there ,主语是复数形式,因此谓语用are,不然的话,要用is,如：There is only one student in the room.
如果不了解这一点,在写句子的时候就容易出错,如有的人写了这样一个句子：There were five students took part in the competition.(X 有5个人参加了比赛.)students 后面不可以再用谓语了,因为其谓语已经在前面存在了,这个句子要改成：There were five students who took part in the competition.(

形式主语是there
谓语是are

主语是five students
谓语: are
后面是状语

主语...five students
谓语.... are
状语 in our band；there
不过这是一个固定的句型。可以看做是There置于句首，后面用倒装。