An infinitive is the basic form of a verb. In English, we express it as “to + the verb.” For example, to give, to run, to sleep, to travel, to speak.
An infinitive is “split” when an adverb is placed between the word to and the verb. The most famous example is from the opening of the original Star Trek episodes. (I have four brothers; go easy on the nerd jokes.)
“to boldly go where no man has gone before”
Notice the adverb boldly between to and go.
So who cares if you put an adverb in the middle of an infinitive? The truth: Not too many people. Writers, grammarians, editors–sure, we might care. But most people won’t even notice them.
If most people glance right over them, why do writers, grammarians, editors, and the ilk get our their red pens for split infinitives? Technically, when you split an infinitive, you are splitting something that is meant to be treated as one word. I’m no linguist, but in the few languages I’ve studied, infinitives are generally expressed in one word, not two like they are in English. For example, “to speak” is only one word in Italian (parlare), German (sprechen), and Spanish (hablar).
Stylistically, I think most purists just feel that sentences flow better when the infinitive is not split, but honestly, I’ve rewritten sentences to get rid of split infinitives and decided I actually liked the split version better!
So should you care? If you’re writing to impress someone who might be a stickler, avoid it. Otherwise, write on! Most people won’t even notice. Grammar Girl even refers to it as an “imaginary grammar rule.”
Do you speak another language? How do you say “to speak” in that language? Can you express it in one word or do you need two?