Answer:
Complexity
Written language is relatively more complex than spoken language. Written language has longer words, it is lexically more dense and it has a more varied vocabulary. It uses more noun-based phrases than verb-based phrases. Written texts are shorter and the language has more grammatical complexity, including more subordinate clauses and more passives.
Formality
Academic writing is relatively formal. In general this means that in an essay you should avoid colloquial words and expressions.
Precision
In academic writing, facts and figures are given precisely.
Objectivity
Written language is in general objective rather than personal. It therefore has fewer words that refer to the writer or the reader. This means that the main emphasis should be on the information that you want to give and the arguments you want to make, rather than you. For that reason, academic writing tends to use nouns (and adjectives), rather than verbs (and adverbs).
Explicitness
Academic writing is explicit about the relationships int he text. Furthermore, it is the responsibility of the writer in English to make it clear to the reader how the various parts of the text are related. These connections can be made explicit by the use of different signalling words.
Accuracy
Academic writing uses vocabulary accurately. Most subjects have words with narrow specific meanings. Linguistics distinguishes clearly between "phonetics" and "phonemics"; general English does not.
Hedging
In any kind of academic writing you do, it is necessary to make decisions about your stance on a particular subject, or the strength of the claims you are making. Different subjects prefer to do this in different ways.
A technique common in certain kinds of academic writing is known by linguists as a ‘hedge’.
Responsibility
In academic writing you must be responsible for, and must be able to provide evidence and justification for, any claims you make. You are also responsible for demonstrating an understanding of any source texts you use.
Organisation
Academic writing is well organised. It flows easily from one section to the next in a logical fashion. A good place to start is the genre of your text. Once you have decided on the genre, the structure is easily determined..
Planning
Academic writing is well planned. It usually takes place after research and evaluation, according to a specific purpose and plan.
