The house of grammar has many rooms, and some of them are haunted. Despite the best efforts of grammatical exorcists, the ghosts of dead rules and the spirits of imaginary taboos are still rattling and thumping about the old place.
It's no longer considered a crime to split an infinitive or end a sentence with a preposition, for example, but the specters of worn-out rules have a way of coming back to haunt us. In the interest of laying a few to rest, let's dedicate to each a tombstone, complete with burial service. May they rest in peace.
: Don't split an infinitive.
An infinitive is a verb in its simplest form, right out of the box. It can usually be recognized by the word to in front of it: Blackbeard helped him to escape. But the to isn't actually part of the infinitive and isn't always necessary: Blackbeard helped him escape. As a preposition, a word that positions other words, the to lets us know an infinitive is coming.
The truth is that the phrase "split infinitive" is misleading. Since to isn't really part of the infinitive, there's nothing to split. A sentence often sounds better when the to is close to the infinitive: Dilbert decided to mention dating in the workplace. But there's no harm in separating them by putting a descriptive word or two in between: Dilbert decided to discreetly mention dating in the workplace.
A sentence like that sounds natural because in English, the best place for an adverb (like discreetly) is right in front of the word it describes (mention). Where else could discreetly go? Putting it anywhere else—say, before or after decided or dating—would change the meaning.
Sometimes, rearranging the words to avoid a "split" can be ridiculous. Try it with this example: Kiri's landlord wanted to flatly forbid singing. Or this one: He threatened to more than double her rent. Or this: The landlord is expected to strongly oppose weaker noise regulations. See?
Writers of English have been merrily "splitting" infinitives since the 1300s. It was perfectly acceptable until the mid-nineteenth century, when Latin scholars—notably Henry Alford in his book A Plea for the Queen's English—misguidedly called it a crime. (Some linguists trace the taboo to the Victorians' slavish fondness for Latin, a language in which you can't divide an infinitive.) This "rule" was popular for half a century, until leading grammarians debunked it. But its ghost has proved more durable than Freddie Krueger.
So it's fine to split—just don't go overboard. Not: Dilbert decided to discreetly and without referring to the boss's secretary mention dating in the workplace.
: It's wrong to end a sentence with a preposition.
We can blame an 18th-century English clergyman named Robert Lowth for this one. He wrote the first grammar book saying a preposition (a positioning word, like at, by, for, into, off, on, out, over, to, under, up, with) shouldn't go at the end of a sentence. This idea caught on, even though great literature from Chaucer to Shakespeare to Milton is bristling with sentences ending with prepositions. Nobody knows just why the notion stuck—possibly because it's closer to Latin grammar, or perhaps because the word "preposition" means "position before," which seemed to mean that a preposition can't come last.
At any rate, this is a rule that modern grammarians have long tried to get us out from under.
: Data is a plural noun and always takes a plural verb.
It's time to admit that data has joined agenda, erotica, insignia, opera, and other technically plural Latin and Greek words that have become thoroughly Anglicized as singular nouns taking singular verbs. No plural form is necessary, and the old singular form, datum, can be left to the Romans. (Media, it seems, is going the same way, though it's not there yet. Ask again in a few years.)
: It's wrong to start a sentence with and or but.
But why is it wrong? There's no law against occasionally using and or but to begin a sentence.
Over the years, some English teachers have enforced the notion that and and but should be used only to join elements within a sentence, not to join one sentence with another. Not so. It's been common practice to begin sentences with them since at least as far back as the tenth century. But don't overdo it or your writing will sound monotonous.
: Don't split the parts of a verb phrase (like has been).
This has never been a rule. It's a by-product of the famous superstition about splitting an infinitive (see the first tombstone).
: None is always singular.
Not always. In fact, none is more likely to be plural.
Many people seem to have been taught (mistakenly) that none always means "not one" (as in, None of the chickens is hatched). But most authorities have always believed that none is closer in meaning to "not any (of them)" than to "not one (of them)." So it's considered plural in most cases and takes a plural verb: None of the chickens are hatched.
None is singular only when it means "none of it"—that is to say, "no amount." (None of the milk was spilled.)
If you really do mean "not one," say "not one."
: Use It is I, not It is me.
Here's another ordinance that's out of date. It's OK to use It is me, That's him, It's her, and similar constructions, instead of using the grammatically correct but more stuffy It is I, That's he, and It's she.
Similarly, it's fine to say, Me too. The alternative, I too, is still grammatically correct, but unless you're addressing the Supreme Court or the Philological Society, you can drop the formality.
: Don't use who when the rules call for whom.
We can't dump whom entirely, at least not just yet. But many modern grammarians believe that in conversation or informal writing, who is acceptable in place of whom at the beginning of a sentence or clause (a clause is a group of words with its own subject and verb): Who's the package for? You'll never guess who I ran into the other day.
Where whom should be used after a preposition (to, from, behind, on, etc.), you can substitute who by reversing the order and putting who in front. "From whom?" becomes "Who from?"
: Never use a double negative.
A piece of advice on double negatives: "Never say never."
The double negative wasn't always a no-no. For centuries, it was fine to pile one negative on top of another in the same sentence. Chaucer and Shakespeare did this all the time to accentuate the negative. It wasn't until the eighteenth century that the double negative was declared a sin against the King's English, on the ground that one negative canceled out the other. (Blame the clergyman and grammarian Robert Lowth, the same guy who decided we couldn't put a preposition at the end of a sentence.)
As for now, stay away from the most flagrant examples (like I didn't do nothing or You never take me nowhere), but don't write off the double negative completely. It's handy when you want to avoid coming right out and saying something: Your blind date is not unattractive. I wouldn't say I don't like your new haircut.
: Use have got, not have gotten.
People who take this prohibition seriously have gotten their grammar wrong.
At one time, everyone agreed that the verb get had two past participles: got and gotten. (The past participle is the form of a verb that's used with have, had, or has.) It's true that the British stopped using have gotten about 300 years ago, while we in the Colonies kept using both have got and have gotten. But the result is not that Americans speak improper English. The result is that we have retained a nuance of meaning that the unfortunate Britons have lost.
When we say, Bruce has got three Armani suits, we mean he has them in his possession. It's another way of saying he has them.
When we say, Bruce has gotten three Armani suits, we mean he's acquired or obtained them.
It's a very useful distinction, and one that the British would do well to reacquire.