"... to boldly go where no one has gone before."
This famous line (from Star Trek, if you aren't familiar) also happens to break a "rule" that was once taught to youngsters who were learning English grammar: "Never split an infinitive." In this post, I explain why it is acceptable—even preferable—to split an infinitive by adding an adverb between "to" and the root verb.
What Is An Infinitive?
First, let's define "infinitive" for those of you who are not familiar with that term. The infinitive of a verb is its base form; in English, it is always written as "to" + the root verb. Some examples are "to be," "to have," and "to elevate." Infinitives have no subjects, and they are typically used in combination with other verbs, as in these examples (the infinitives are underlined in the examples throughout this post):
I want to visit Paris in the next three years.
Loretta helped me to put the new bookcase together.
Cotton swabs are meant to be used only on the outer ear.
In most cases, including these examples, infinitives are used after their sentences' main verbs (which are "want," "helped," and "are meant" in the examples). Note that other words can be placed between the main verbs and the infinitives (such as the object "me" in the second example). In addition, infinitives can come before the main verbs in some unusual sentence structures. These sentences can always be rephrased more conventionally, with the infinitive after the main verb. Consider this sentence in two ways:
To see the screen better, Brendan put on his glasses. Brendan put on his glasses to see the screen better.
As you can see, in the typical phrasing, the infinitive "to see" goes after the main verb ("put"). Either version is fine, however.
Infinitives can also be used as nouns. In is example, the infinitive is the subject of the sentence:
To abstain from alcohol is a requirement of many faiths.
This construction sounds very formal, but it is grammatical.
What Is The "Rule," And Why Can I Ignore It?
Some old-fashioned grammarians argued that, because an infinitive is a unit made up of two words, it should not be split up by placing other words between the "to" and the root verb. This is somewhat logical, but it also ignores the way that English works. In addition, strictly adhering to this "rule" can cause awkward-sounding sentences.
English contains many patterns—parts of speech that typically come immediately after other parts of speech. Here are some common examples (we've already talked about the first one in this post!):
Infinitives usually come immediately after the sentences' main verbs.
Verbs usually come immediately after their subjects.
Objects usually come immediately after their verbs.
Adjectives/adverbs usually come immediately before the words that they modify.
There are many exceptions to these patterns, as I have already shown with the first pattern. That's because these patterns are defaults, not rules; English grammar is very flexible. Indeed, English is a language of exceptions (which helps explain why it can be difficult for nonnative speakers to learn).
The pattern with split infinitives is the same: Yes, the root verb typically comes immediately after the word "to," but there is no grammatical reason why this should be a strict rule. Often, adding an adverb in between can make a sentence sound more natural and dynamic. Consider this sentence, in which an adverb (in green) splits an infinitive:
The workers sought to quickly repair the dam before flooding could occur downstream.
This sentence sounds perfectly natural, and it clearly communicates the meaning. If we were to rephrase this sentence to follow the "rule" against splitting infinitives, we would have three other options. See if you can figure out why the other options are worse:
The workers quickly sought to repair the dam before flooding could occur downstream. The workers sought quickly to repair the dam before flooding could occur downstream. The workers sought to repair the dam quickly before flooding could occur downstream.
The first alternative changes the meaning of the sentence; "quickly" now modifies "sought" instead of "repair." The second alternative sounds awkward, and it is unclear which of the two verbs "quickly" is meant to modify. The third alternative is better than the first two, but "quickly" is far from the verb it modifies. Generally, it is better to place the adverb as close to its verb as possible. Thus, the original sentence is the best version. There is no reason for it to be rephrased.
The same sorts of issues arise for other examples. For some sentences, you certainly can write the sentence without the split infinitive; however, the other version is never better than the one with the split infinitive. Indeed, the version with the split infinitive will often be more effective because it better directs the emphasis toward the root verb. Consider these two versions of the same sentence:
Reginald tried to discreetly look at Priyanka's answer sheet. Reginald tried to look discreetly at Priyanka's answer sheet.
Both versions are grammatical and relatively clear. However, the first version—with the split infinitive—is more effective because it places the adverb immediately before "look," thus providing a stronger emphasis.
When Should Split Infinitives Be Avoided?
There are only a few times when you need to change a split infinitive. The first is when something other than a single adverb comes between "to" and the root verb. If another part of speech splits the infinitive, always rephrase; this rarely happens in native English speakers' writing, but nonnative speakers sometimes do this because they are following the patterns of their native tongue. For instance, this sentence splits the infinitive with a prepositional phrase:
Riley wanted to on her birthday play at the trampoline park.
It should be rephrased as follows:
Riley wanted to play at the trampoline park on her birthday.
In addition, consider rephrasing if the infinitive is split with more than one adverb, or with a longer adverbial phrase. Having more than one word between "to" and the root verb can cause difficulty for readers. For instance, these examples are grammatical but a bit awkward to read:
Alton said to always simply juice citrus fruits with one's hands rather than buying a new tool.
Deliberate as always, Min sought to slowly, and with great care, open the present.
They would be better phrased with a one-word adverb or without the split infinitive entirely:
Alton said to always juice citrus fruits with one's hands rather than buying a new tool.
Deliberate as always, Min sought to open the present slowly, and with great care.
Finally, when using a split infinitive, make sure that the adverb you are using is meant to modify the verb in the infinitive. If it is meant to modify another word (such as the sentence's main verb), then move it accordingly. Consider this example:
Elena spoke up to quickly dispel the commissioners' misconception.
This is correct if you are trying to say that Elena wanted to dispel the misconception quickly. However, it is more likely that the intent is to say that she quickly spoke up. In that case, the emphasis should be on "spoke up":
Elena quickly spoke up to dispel the commissioners' misconception.
That's it! In short, as long as you are careful, split infinitives are not just acceptable but helpful. They can even add flavor to your writing.
Do you have any questions about infinitives or how to correctly split them? If so, please leave a comment or email me at firstname.lastname@example.org. I'd love to hear from you.