我没有看过你前面的文章，但是以我的理解应该是每个人的水平不一样，或者他们的理解不一样，用汉语表达一种方式有时候有很多种表达方式，都可以，没有对错之分

I would say there was only one error in that essay, which was 一首王力宏歌. I can feel that you did it carefully. Sometimes the word 的 is omissible, sometimes it's not, and sometimes it depends on personal style. Like in English, there're different ways to express things in Chinese. It's good to learn these different ways and you can just pick up the one you prefer as long as it's acceptable. For me the way you wrote that essay is, honestly, not only acceptable (except for that 的), but also nice. It somehow has a conciseness and simplicity of style actually :) To say 我學中文學了兩年了 or to say 我学中文两年了 is just about style. However, you can't say 我学中文了两年. Both "verb+object+repeat verb+how long+了" and "verb+object+how long+了" are correct. For examples: 我等她等了两年了. / 我等她两年了. 我打球打了三年了. / 我打球三年了... Just use the one you like. And you can also say 我打三年球了 but it's not normal to say 我等三年她了. Why? This is not about grammar, I guess it's just that people find 我等三年她了 not very smooth-sounding or somehow. :) Hope that helps!

每个人说话的习惯不一样，有的人可能仅仅想让你的话容易被他听懂就好，有的人却在努力让你的话听起来更符合让他舒服的说话方式。这里边真的没有对错之分。另外你应该知道，不论何种语言，写出来和说出来的含义是有区别的。在这里你更多能获得的是中国人写的表达习惯。如果你想提升自己的口语，我建议你写成对话的形式，如： 今天我去商店了，以下是我和售货员的对话 ， 售货员：你好，你想买什么？ 我：你好，我想买iphone4s. 希望我的话能让你明白。 如有需要，我会用英文再说一遍。

it's true you can express in different ways the same thing in chinese. A large percentage of your essay is understandable, but if you want to be more native in your expression, you should pay attention to the part where someone made corrections for you

I pay less attention to your article. Because, you write in English. correciton=修改 请看我的第一篇文章《介绍史曼尼》，很多中国人给我修改了，但是为什么每个人的修改都不一样呢，有的人写了很多，有的人写了一点。 You are very luck, because there are many Chinese to correct your article. When I write a article in italian, I have to wait one day, then maybe there is ONE person would give me a correction.