Academic writing is a task which is done mostly by students. It is also done by academics in the academe and researchers in the field of research in any field. It is also the job of the one being paid to do it. Whatever specific case it is done, it is linear. This means that one central point or theme is involved and each part of the writing contributes to the main argument and without digressions or repetitions. Your goal in this task is not to amuse or entertain but to inform or express your educated opinion. Aside from being a form of writing, it is also considered a different language itself. What is important is that you know that this kind of writing is complex, formal, objective, explicit, hedged and responsible. It is precise and accurate.
As a language, academic writing is complex. To start with, writing alone is more complex than speech. When you write, you use more words and longer sentences. Writing is more dense lexically than speaking. A more varied vocabulary is involved. If you work as a writer especially in the academic field, you will use more noun-based phrases then verb-based ones. Grammar is more complex and there will be more subordinate clauses and passives.
Being formal, precise, objective, explicit and accurate and the need to hedge and be responsible are also salient features of academic writing. If you will take this task as a job you will have to be an expert and professional regarding these. It is basic that you avoid colloquial words and expressions when expressing your thoughts and communicating your message. Also, you should be precise everytime you present facts and figures. As a writing, your language should be objective in general and not personal. To do this, you have to limit reference to yourself as the writer and to your readers. Emphasize on the information that you aim to give and on the arguments which you are set to make, not on yourself in whatever specific field of writing you are in like legal writing jobs.