8 Modules on critical aspects of communication skills. System makes next module accessible only after you complete the activities of previous one, thus forcing application to life on a regular basis. Usually doable in one month.

A course on essentials of writing English easily, ideally suited for the basic users.  

Emphasis on correcting mistakes of grammar, punctuation and usage, normally committed by such users. A comprehensive tutorial covering the gap between theoretical knowledge of grammar and its application. Also, several other resources and numerous exercises.

Not so much to learn grammar from scratch, as to avoid wrong grammar.

A free sampler course is available to look into this one. Look up course entitled  'Sampler' in this category i.e. English language, to get a good peep into this course.

A course for the advanced user of English - those who know grammar well and write grammatically correct but verbose, indirect and clichéd English. Emphasis on reducing verbosity and improving directness & clarity. Guidelines to write culture-free English and thus reduce burden on non-native English readers. In addition, adequate coverage of typical errors in grammar and usage, even by advanced users.

free sampler course is available to look into this one. Look up course entitled  'Sampler' in this category i.e. English language, to get a good peep into this course.