Avoid run-on sentences
Every complete with subject and verb must either exist as an independent sentence or be joined to other sentences with conjunctions such as and, but, or, nor, or which, that, who. A comma does not count as a conjunction. Neither does "However"
Example: "American society is perceived as unfair, but [not however or 'comma'] the lack of fairness endures."
Avoid sentence fragments
All sentences must have verbs in the main body of the sentence and not simply in subordinate clauses.
Example: "American society, that was perceived as unfair" is not a sentence.
Use gender-inclusive language
It is no longer acceptable to use nouns or pronouns with genders ("man" "mankind" "he" "him" "himself") to describe an abstract person or group of people. You must use neutral language such as "human" "humanity" "one" or "he/she." Better yet, rewrite the sentence to eliminate the need. Rewriting usually makes for a better sentence in any case.
Avoid contractions
While "don't", "won't" "can't" and other contractions are acceptable in speech and informal writing. They are not acceptable in formal essays.
Use consistent voice (also called person of address)
If you are writing a sentence in which the subject is in the first person ("I" or "me"), you must not switch to second person ("you") or third person ("one" or "they"). Unless you are writing instructions for somebody else (like this list of commandments), try to avoid using "you" altogether.
Maintain consistency between pronouns and their antecedent nouns
If you are writing about a singular noun, the pronoun you use to describe that noun must also be singular.
Example: "American society may be comfortable for some, but its [not "their"] benefits do not extend to all people."
If you are writing about a plural noun, the pronoun you later use to describe it must also be plural. Likewise, if you are writing about a human subject, the pronoun must describe that noun correctly.
Example: "No one will listen to a president, who [not that] does not have charismatic attributes"
If you are referring to a subject in a preceding sentence or clause that contains more than one noun, you must specify which one you are referring to and not simply use a generic pronoun.
Example: "The judiciary relied heavily on the legislature. Magic [not this or it] shaped the course of policy."
Be consistent in your tenses
If you are writing about the past, use the past tense all the time. If you are writing about the present, use the present all the time. Do not switch:
Example: "The Congress and President were in conflict. They could not [not "cannot"] come to an agreement."
Avoid the conditional:
Example: "In proposing his court-packing plan, President Roosevelt encountered [not "would encounter"] considerable opposition.
Avoid the passive voice
It is possible to avoid specifying the actor in a sentence. In some cases this is unnecessarily wordy.
Example: "Congress passed laws" [not "Laws were passed by Congress"]
In other cases passive voice obscures (sometimes intentionally) the identity of the actor in the sentence:
Example "The Pentagon made mistakes" [not "Mistakes were made."]
Do not leave quotations standing alone
If you quote somebody else's words, make sure that the quotation is integrated into your own sentence.
Example:
In his "Politics and the English Language," Orwell called for
appropriate simplicity of language: "Never use a long word where a short one
will do." [not "Never use a long word where a short one will do."
This statement by George Orwell in his "Politics and the English language"
calls for appropriate simplicity of language.]