There are a lot of things to do 为什么用are?

There are a lot of things to do 为什么用are?
There are a lot of things to do 为什么用are?

There are a lot of things to do 为什么用are?
things 是复数
所以be动词用复数are

things是复数

lot of things 是复数，所以要用are

a lot of things 是复数、要主谓一致。所以用are

a lot of用来修饰可数名词复数和不可数名词 things是可数名词复数 所以用are

there be 句型中be的单复数是有其后所接的名词来决定的。该句中 a lot of things 是复数名词所以用are。

there are是这有，固定搭配
there are many thing与there are many apples一样的直译
（这里有很多事） （这里有很多苹果）
就是这有，a lot of为副词可以不看，are后是负数，things是负数。