i have found that he is --than john

题目

i have found that he is --than john
more an effcienient worker 为什么请解释
我问的是为什么是 more an effcienient worker 顺序而不是an more effcienient worker

答案

I found that he is an more efficient worker than John.
我发现他的工作效率比john更高.