Like many languages, English is constantly changing. And today it is changing faster than ever. Mobile phones, social media, increased travel and other things have connected the world more closely and changed how we speak...and write.

The changes are happening so quickly that English dictionaries now add hundreds of words and phrases every year.

And, just as these things change, so too do grammar rules.

In an earlier Everyday Grammar program, we told you about a few grammar rules that are dying.

Today, we will tell you about three rules that some experts say are outdated and never had strong reasoning behind them. Breaking these rules is acceptable in all but the most formal writing, such as business letters and some kinds of academic writing.

We will begin with one of the most common rules:

Number 1. "Never split an infinitive."

Generations of English speakers have been taught that it is wrong to split an infinitive. But, today, even respected dictionaries such as the Oxford English Dictionary say there is no worthy defense for the rule.

Infinitives are the unchanged forms of verbs. You can identify one by the word "to" in front of a verb. For example, "to have," "to go" and "to make" are all infinitives. Split infinitives happen when we put an adverb in the middle. Here's an example:

He began to flatly deny the abuse charges.

In this sentence, the infinitive "to deny" is separated by the adverb "flatly" and it sounds very natural.

But, when you use the "no split infinitives" rule, the adverb can go in two places – either before the infinitive:

He began flatly to deny the abuse charges.

...or at the end of the sentence:

He began to deny the abuse charges flatly.

While the first example sounds fine, the second is mechanical and feels unnatural.

Patricia O'Connor is a former New York Times Book Review editor and writes about English. In her book, "Woe is I," she writes that the rule on split infinitives comes from a famous 1864 British grammar book that tried to apply rules of Latin to English.

Today, even the writing style guidebooks of large media agencies reject this old-fashioned grammar rule.

So, unless you have a teacher or employer who has banned split infinitives, this is a rule you can dismiss.

Many experts say you can now break some old grammar rules in English.

Number 2: "Never begin a sentence with a conjunction."

The words "and," "but" and "or" come from a group of words called coordinating conjunctions. These words connect two or more structures, such as sentences or clauses. For example, "I washed the car and I took the dog for a walk" connects two complete sentences. So, technically, you can break these into separate sentences: "I washed the car. And I took the dog for a walk."

Many grammar books (and teachers) teach that you should not begin a sentence with "and" "but" or "or." But surely you've noticed that, here at VOA Learning English, we break this old rule... a lot.

And we are not alone. Many other news agencies, books, websites and other media break the rule.

In his book "The Story of English in 100 Words," linguist David Crystal says that writers have begun sentences with "and" and "but" since the 16th century, including William Shakespeare. He explains the rule's unusual history:

During the 19th century, some schoolteachers took against the practice of beginning a sentence with a word like "but" or "and," [probably] because they noticed the way young children overused them in their writing.

Yet, instead of limiting usage, Crystal says, teachers banned conjunctions for opening sentences. This has had a lasting effect, creating the idea that sentences beginning with these conjunctions are incomplete. That is untrue.

However, if you are going to break the rule, find out if your school or job permits it. In addition, you must do it correctly, which means: Know what a complete sentence is. For instance, "And it's good" is a complete sentence; it has a subject and predicate but "And is good" is not; it's missing a subject.

Lastly, don't start sentences with these conjunctions too often. It can become tiresome for your reader.

Now, onto our third old rule.

Number 3: "Use 'each other' for two and 'one another' for more than two."

Traditionally, we have been taught that "each other" refers to two people or things and "one another" refers to more than two people or things. We call these phrases reciprocal pronouns.

Here's an example with "each other":

The two animals looked at each other.

And here's an example with "one another":

Family members usually like one another.

Today, this rule is disappearing, and for good reason. Respected dictionaries, such as the American dictionary Merriam-Webster, seem to think it has always been nonsense. Merriam-Webster writes that good writers have used "each other" and "one another" interchangeably since at least the 16th century.

Others agree. In their book "Longman Guide to English Usage," British grammar experts Janet Whitcut and Sidney Greenbaum write that "there is no basis" for the rule.

So, unless told otherwise, you can use "each other" and "one another" interchangeably in any writing situation.

Know what is permitted

While these three grammar rules have strange beginnings and are disappearing from modern English, it is important to know the writing style of your workplace, school or university. If you are ever unsure about current opinion on a grammar rule, the safest thing to do is to use it.

I'm Alice Bryant.

Alice Bryant wrote this story for Learning English. Caty Weaver was the editor.Do you use the rules from today's program? How do you feel about them changing? What are some English grammar rules that you like or dislike? Write to us the Comments area.

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