William Safire

“Not long ago, I advertised for perverse rules of grammar, along the lines of "Remember to never split an infinitive" and "The passive voice should never be used." The notion of making a mistake while laying down rules ("Thimk," "We Never Make Misteaks") is highly unoriginal, and it turns out that English teachers have been circulating lists of fumblerules for years. As owner of the world's largest collection, and with thanks to scores of readers, let me pass along a bunch of these never-say-neverisms:

* Avoid run-on sentences they are hard to read.
* Don't use no double negatives.
* Use the semicolon properly, always use it where it is appropriate; and never where it isn't.
* Reserve the apostrophe for it's proper use and omit it when its not needed.
* Do not put statements in the negative form.
* Verbs has to agree with their subjects.
* No sentence fragments.
* Proofread carefully to see if you any words out.
* Avoid commas, that are not necessary.
* If you reread your work, you will find on rereading that a great deal of repetition can be avoided by rereading and editing.
* A writer must not shift your point of view.
* Eschew dialect, irregardless.
* And don't start a sentence with a conjunction.
* Don't overuse exclamation marks!!!
* Place pronouns as close as possible, especially in long sentences, as of 10 or more words, to their antecedents.
* Writers should always hyphenate between syllables and avoid un-necessary hyph-ens.
* Write all adverbial forms correct.
* Don't use contractions in formal writing.
* Writing carefully, dangling participles must be avoided.
* It is incumbent on us to avoid archaisms.
* If any word is improper at the end of a sentence, a linking verb is.
* Steer clear of incorrect forms of verbs that have snuck in the language.
* Take the bull by the hand and avoid mixed metaphors.
* Avoid trendy locutions that sound flaky.
* Never, ever use repetitive redundancies.
* Everyone should be careful to use a singular pronoun with singular nouns in their writing.
* If I've told you once, I've told you a thousand times, resist hyperbole.
* Also, avoid awkward or affected alliteration.
* Don't string too many prepositional phrases together unless you are walking through the valley of the shadow of death.
* Always pick on the correct idiom.
* "Avoid overuse of 'quotation "marks."'"
* The adverb always follows the verb.
* Last but not least, avoid cliches like the plague; seek viable alternatives."

(New York Times, November 4, 1979; later also published in book form)”
― William Safire, Fumblerules: A Lighthearted Guide to Grammar and Good Usage

“Never assume the obvious is true.”
― William Safire