Split Infinitive


As most of your writing in class is to be done in formal English, I will always correct your use of split infinitives. However, you should know the history and the different opinions about its use. The following comes from Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993


A split infinitive consists of the function word to, followed by an adverb (usually an -ly adverb), followed by an infinitive: to happily conclude, to weakly demur, to needlessly suffer.

The construction got its name and ill fame many centuries after it first appeared in English (indeed, it was good English when this nation began), but during the nineteenth and early twentieth centuries great numbers of split infinitives appeared in print, and many complaints followed.

One possibly after-the-fact reason for the objections was that since Latin and Greek infinitives were not (indeed, as single words, could not) be split, neither should English infinitives, even though they often came in two parts, to plus infinitive, and so were vulnerable to being split by adverbs.

Or the crusade may have been launched by people seeking rules about where to put adverbs, the location of which is very flexible in the English sentence. Certainly split infinitives sometimes can cause very clumsy sentences, as in "We seek to adequately and sincerely persuade you of our gratitude." Unfortunately, the rule against splitting, although simple, did not take actual usage into account.

Ideally, English adverbs immediately precede the verbs they modify, as in "He stoutly defended his opinion," or come at the end of the predicate and modify it or the whole sentence, as in "He defended his opinion stoutly," or modify the entire sentence rather than just the verb by appearing at the beginning of the sentence, as in "Stoutly, he defended his opinion." These generalizations also describe the placement of adverbial modifiers of infinitives; these adverbials, however, can be ambiguous in writing, where intonation is not available to assist in specifying grammatical relationships. This potential for confusion probably accounts for the popularity of the split infinitive, which eliminates all possibility of ambiguity. Consider these three sentences:

—"The driver is instructed periodically to check the oil level."
—"The driver is instructed to periodically check the oil level."
—"The driver is instructed to check the oil level periodically."

The first, which avoids splitting the infinitive, is possibly ambiguous, at least in writing: is the driver instructed periodically, or is it the checking that’s to be done periodically? The second splits the infinitive but makes it clear that periodically modifies the verb check. The third doesn’t split the infinitive, but unless it’s punctuated as a sentence modifier, it could conceivably be thought to modify instructed rather than to check. It’s a weak ambiguity, but readers can be notoriously obtuse sometimes.

Today, split infinitives continue to appear often in Standard speech and even in Edited English, especially in sentences where to avoid them would be clumsier and less effective than to use them. Conservative practice still tries to avoid them, especially at Planned, Oratorical, and Formal levels, particularly when they’re not necessary for grammatical clarity, and it uses them only when they seem clear, add emphasis, and help avoid contorted syntax. Best advice: split an infinitive in speech whenever you wish, if the result sounds clear and unambiguous, but in writing follow the conservative path, especially when you’re uncertain of your readers’ expectations and sensitivities in this matter.