Quoth the owl:
I suspect the whole problem lies in the English language school syllabus and the way it is taught. I think we would be able to make people write well if we expanded the Literature component and forgot about teaching grammar, comprehension, vocabulary, and the works.I don't totally agree with that no-grammar-vocab-comprehension thing, but this nocturnal mouse-eater does have a point.
Just concentrate on Literature and writing. People are unable to write in English because they don’t think in the language. Lacking practice makes it very difficult to write. Once people start to read and write, everything will fall into place. They will understand sentence structure. No amount of grammar lessons will make people understand syntax.