求牛人英语改错~求英语牛人帮忙把下面这段话改错一下~语法错误~

求牛人英语改错~求英语牛人帮忙把下面这段话改错一下~语法错误~
The purpose of this article is to analyse and discuss the example through colour theories and applications.This example comes from the movie “The Departed”.(Appendix 1) As why I choose this movie poster,there are several reasons as follow.Firstly,a poster is one of graphic design.Moreover,there are lots of theories and applications to show in this poster.In this article,the range of the colour will be identified and,in the second part,the poster will be deeply analysis and discussion based on the colour theory and functional.

The purpose of this article is to 中式说法
This article is designed to .
第一句：This article is designed to analyse and discuss an example (an instance也可,后面才知道你讲的是哪个例子,这里要泛指用不定冠词） using（through是通过,你想表达通过什么方法,用using或via） colour theories and applications.
As why I choose this movie poster,there are several reasons as follow.语法错（前有why后有reason,这两个词不一起使用在一个句子中的）
The reasons that I choose this movie poster are as follow
there are lots of theories and applications to show in this poster
在海报展现出很多理论,理论是被show出来的,用被动,或索性不用to show也行
In this article,the range of the colour will be identified and,in the second part,the poster will be deeply analysis and discussion based on the colour theory and functional.
想表达什么,混乱,语法错很多哦
要知道你的意思再改
另外,是不是没有完结,因为只有firstly,后面的secondly,thirdly呢?
再问： 最后一部分想说文章主要分成两部分，第一个部分是说出色彩的范围（range of colour）第二个部分就是深层次的分析这海报
再答： 我是说你理由还没有完全说完呢，得先把理由一、二、三说完吧 再说你文章的结构
再问： moreover后面的就是第二点
再答： 那不能用moreover啊，得跟着firstly用secondly啊，还有第三点的话用thirdly，否则就是不对的啊
再问： 那最后一部分应该怎么修改呢？
再答： 我就不跟你讲文章的逻辑了，就文字论文字 In this article, the range of the colour will be specified（identified是身份识别，你的意思想表达阐述吧，用specify这个动词） and followed by a deep analysis and discussion of the poster based on the colour theory and functionals.