Just what is an infinitive, and how does one split it? The answer is pretty simple: an infinitive is the basic, unconjugated form of a verb. In English, infinitives take the form of “to ____.” To read, to run, to imagine. From this basic infinitive, the verb can be transformed to meet many needs of speech:
You should have eaten.
There are many other forms a verb can take—all of them drop the “to” from the infinitive form of the verb and then alter the primary word to suit the context of the sentence. But that basic “to ____” form is the starting point.
So, how do you split the infinitive form of a verb? Simple. You just place an adverb between the “to” and the rest of the verb:
She wanted to furiously pound his face in.
You may have had an English teacher at some point who considered splitting infinitives to be the eighth deadly sin—an unforgivable perversion of the language. It’s really not, though it is something that you should do only infrequently.
Why is splitting the infinitive considered so bad? Well, to answer that we need to delve a bit into (a simplified version of) the history of the language.
A Simplified History of English
A long time ago, out there in Europe, Latin was considered the crème de la crème of languages. Most European languages had evolved out of Latin, and it was generally considered the “holy” language of academics and the church. The language that would eventually come to be known as English, meanwhile, was a young hodgepodge of barbarian speech and “proper” languages—the bastard child of a dozen different parents. It lacked a consistent grammatical structure and written form.
However, a number of scholars who spoke this proto-English were beginning to appear, and they wanted to make their language a respectable equal with all of those other European languages. They set about to codify and clarify the rules of the language, and found a large amount of gaps where there were no consistent rules to English. Whenever that happened, they simply borrowed rules from the most respectable language around: Latin.
Why was this a problem? Well, here’s the infinitive form of the verb “to read” in Latin: legere. Notice how it differs from the English version—it’s only one word. So because it is literally impossible to split an infinitive in Latin, it was decided that it wouldn’t be allowed in English, either.
Back to the Present Day
Doesn’t that seem a little silly nowadays? We’re refusing to make use of a relatively unique ability of our language because a once-popular language couldn’t split an infinitive. Well, I don’t hold to that. There are times when you just need to split an infinitive, dang it! For instance:
That’s probably the most famous split infinitive around. Sure, they didn’t have to split the infinitive, but try re-writing that line without it:
Boldy to go where no one has gone before.
To go boldly where no one has gone before.
To go where no one has gone before.
None of those rewrites have the same power as the original, do they? “To boldly go” is simply the most powerful and moving way to write that sentence. Split infinitives for the win!
However . . .
The potential power of split infinitives notwithstanding, you shouldn’t be using them often. Most of the time, split infinitives simply sound awkward and forced—adverbs are already difficult enough to use well on their own, after all. Compare this sentence that uses a split infinitive:
He needed to quickly devour his meal.
to this sentence that does not:
He needed to devour his meal quickly.
The second one is stronger—it just feels more natural and smooth. Most of the time, your writing will be better off if you avoid splitting infinitives. Just remember, though, that it is an option. The day may come when a split infinitive will strengthen your writing, so know what you’re doing when that time comes.