My name is Diana Tower and I have been teaching English for the past two years in Spain. I am from Canada (Calgary) and I love helping people learn and improve their English. (Just thought I would introduce myself). You can see that I have made some corrections to your essay and I thought I would give you some feedback as well.
The first thing to remember is that you don't need to say English Language...Chinese language etc. Just say English or Chinese.
Also when I wrote "English is the easiest out there" that means existing...like my phone is the best out there...means my phone is the best existing phone right now.
In general I think your writing level is good...a mid intermediate (but it depends on what scale you are refering too...there are many different ones out there). You construct your ideas well, use good connectors to keep everything flowing from one idea to the next and you express your ideas with a nice style and voice.
Watch out for a, the, in/at/on . They are small but tricky.
In general I am not sure what letter grade I would give you. I don't score by letter grades. But I would say that you have a mid-intermediate level...
I hope that helps.
Also, if you would like some more help with your writing, visit the writing section of my website Free writing lessons for all forms of writing. There you can see real letters written by my friend Arturo. You can try to catch his mistakes and then compare what you find with what I found.
If you need any other help, don't hesitate to come to the forum or ask me directly. :)