Clearly your English is better (much, much better!) than my Chinese, but even so without a full understanding of the English language, SEO of an English website is going to prove a huge problem.
I previously developed a Russian language website, with the help of a Russian, and found the SEO aspects almost impossible to master. In the end I left the site to my Russian partner because it was so difficult for me to SEO the site.
The nuances of a language are required knowledge for effective SEO and only the courageous and the very determined will suceed if they are not totally fluent in that language.