This MOOC titled "A Beginner's Guide to Writing in English for University Study" hosted by the University of Reading may be of interest to you if you wish to improve or develop your English writing skills, vocabulary and grammar. https://www.futurelearn.com/courses/english-for-study
Notes for myself:
Can I identify focus and supporting evidence in the essay?
One way to assess it is, at the simplest level, by looking for content, structure/organisation, language/grammar. Or, expressed as three questions: What have you got to say? How do you say it? Are you in line with rules and norms of English expression?
A simple way of constructing individual paragraphs is to use the focus/response pattern.
