Writing Links & Description
http://www.onlineschools.org/online-writing-center/
This website contains much of the basic necessary information needed for good academic writing as well as some checklists for essay sections.
http://esl.fis.edu/grammar/correctText/index.htm
One of the most important aspects of writing that is often overlooked is that of proofreading. This link has a selection of texts that require the reader to identify errors.
https://owl.english.purdue.edu/exercises/
Focuses here include paraphrasing, summarising, clauses and many other aspects of the mechanics of writing.
https://www.thoughtco.com/esl-4133095
Numerous writing tips are combined with grammar exercises here. Not all topics have exercises, but step-by-step descriptions help with process acquisition.
Although this website is specific to IELTS writing, the feedback and notes on the writing section can also be applied to general academic writing.
Many aspects covered in the AE courses such as paraphrasing, nominalization, hedging and others are explained here. Practice exercises with feedback help to reinforce covered content.
https://www.academic-englishuk.com/
Contains some free content for all skills, however, the writing sections are particularly useful. Short tasks are offered with answers to compare and contrast your own with.