I don't think him a man to ( ),for he is always lying.为什么要用rely on ,而不用 be relied

I don't think him a man to ( ),for he is always lying.
为什么要用rely on ,而不用 be relied

因为 be relied 后面加on才对 这里没有
如果是 be relied on 也是对的

to 后 一般跟动词原型 do