Split Infinitives: The Made-Up Grammar “Rule” You Can Definitely Break

Star Trek is an iconic media franchise, bringing audiences legendary characters, exciting storylines, and seemingly endless spin-off shows and movies. But the franchise’s impact goes beyond the entertainment realm: Grammarians have Star Trek to thank for one of the most famous split infinitives of all time. When Captain Kirk logged the Enterprise‘s mission “to boldly go where no man has gone before,” he laughed in the face of a long-standing (and totally made-up) grammatical rule. And thank goodness he did!

The (Sort Of) Rule

Your middle school English teacher might have told you that you shouldn’t split infinitives. But what does that mean?

An infinitive is formed when “to” is added before a verb.

To be or not to be, that is the question

My team wanted to win the championship.

Susan’s friend came over to study for the test.

To climb Mount Everest is an impressive achievement.

The verb must be in its root form (not conjugated for any subject or tense). For example, you’d never see “To climbed Mount Everest is an impressive achievement” because “climb” in that sentence is conjugated for the past tense.

Splitting an infinitive happens when you put another word between “to” and the verb following it:

My team wanted to finally win the championship.

Susan’s friend came over to actually study for the test.

To individually climb Mount Everest is an impressive achievement.

I highlighted those in orange (not red) because the rule to avoid splitting infinitives is iffy at best.

Where’d It Come From?

According to Merriam-Webster, infinitives could not be split in Old English because they were written as single words. We’d never break up a single word today to stick an adverb in the middle (how does “run-quickly-ing” sound?), so it makes sense that split infinitives simply didn’t exist back then.

However, as the language progressed into Middle English, infinitives started to be written as two words. Even back then, in the fourteenth century, writers began splitting those two-word infinitives by putting another word in between “to” and the verb. Although Captain Kirk may have introduced one of the most famous split infinitives, he certainly was far from the first person to do it.

Around the sixteenth century, the British elite decided that the English language needed more grandeur and sophistication in order to reflect and encourage the success of the growing British Empire (according to Einsohn in The Copyeditor’s Handbook). They looked at the incredible power of the Roman Empire and understood that one of the key contributors to its success was the classical Latin language. So they put two and two together and decided that, in order for Britain to achieve equal success, it needed a language as “perfect” as Latin. However, instead of making English perfect in its own way, they just tried to make it as close to Latin as possible (why fix what ain’t broke, right?).

In pursuit of this goal, people came up with all kinds of Latin-based rules to inflict on English. One of those rules was that infinitives could no longer be split. This is a rule in Latin because, like in Old English, infinitives in Latin are single words; therefore, it’s impossible to insert another word into them. But in English, infinitives are decidedly not one word, so does it really make sense to enforce this rule? (Toss in there that the British Empire is no longer, and you lose pretty much every reason to enforce this outdated and nonsensical rule.)

Why It’s Bogus

The main reason why we don’t need the “don’t split infinitives” rule is that there’s no reason to enforce it. A split infinitive that doesn’t inhibit clarity does absolutely no harm to a sentence. But aside from the fact that split infinitives don’t hurt anyone, we need to consider that un-split infinitives can actually cause problems and make sentences sound incredibly awkward.

In The Careful Writer, Theodore Bernstein lists these examples of un-split infinitives that cause confusion in a sentence:

• “The Thanksgiving Day setback was sure to defer further American hopes of keeping pace with the Soviet Union in lunar exploration.” (Does “further” modify “defer” or “American hopes”? If we just split the infinitive and said “to further defer,” it would clear things up.)
• “The Premier proceeded to admonish sharply the ten die-hard Opposition speakers.” (This just sounds awkward—the split infinitive “to sharply admonish” sounds much better.)
• I don’t even know how to un-split these infinitives: “Rumania’s Communist rulers expect that nation’s industrial output to more than double in the next five years.”; “The Governor has decided to all but give up on his minimum wage bill”; “He refused to so much as listen to the prisoner’s appeal.”

Even the prescriptive, rule-loving Chicago Manual of Style agrees that a split infinitive is sometimes the best option: “Sometimes it is perfectly appropriate to split an infinitive with an adverb to add emphasis, clarify meaning, or produce a natural sound.”

Here’s another example of when a split infinitive can clear up a sentence’s meaning:

Billy’s mother decided to introduce gradually more vegetables into his diet. (This sentence sounds unnatural—the “gradually” comes too late.)

Billy’s mother decided gradually to introduce more vegetables into his diet. (This would be great if we meant that the decision was gradual, but what if we meant that she made the decision all at once and the gradual act is the introduction of more vegetables?)

Billy’s mother decided to gradually introduce more vegetables into his diet. (Good—this sentence is clear and not awkward.)

If this post is stressing you out and you really love the “never split an infinitive” rule, that’s totally fine. There are usually ways to re-word sentences so that you can avoid the split infinitive! However, you should always remember to prioritize clarity. If you work to hard to prevent split infinitives, you might end up creating some really weird sentences.

Einsohn notes that the split infinitive is definitely not the only grammar “rule” that isn’t really a rule at all: “As you gingerly tiptoe around the landmines that dot the prescriptive-descriptive battlefield, you will encounter dozens of ‘rules’ that were never really rules, just the personal preferences or prejudices of someone bold enough to proclaim them to be rules.”

Famous Split Infinitives

Here are a couple more famous split infinitives, for your reading pleasure!

“Nor can I blame thee, though it be my lot / To strongly, wrongly, vainly love thee still. —Lord Byron, “Love and Death”

“I knocked gently and rang as quietly as possible, for I feared to disturb Lucy or her mother, and hoped to only bring a servant to the door.” —Bram Stoker, Dracula

“He began to blithely roar at his staff: ‘We’ll wallop ‘im now…'” —Steven Crane, The Red Badge of Courage

Sources:

• The Chicago Manual of Style. 17th ed. Chicago, IL: The University of Chicago Press, 2017.
• Einsohn, Amy. The Copyeditor’s Handbook. 3rd ed. Berkeley and Los Angeles, California: Univ of California Pr, 2011.
• Merriam-Webster. Merriam-Webster’s Dictionary of English Usage. 14th ed. Taunton, MA: QuadGraphics, 2016.