An infinitive verb form with an element, usually an adverb, interposed between to and the verb form, as in to boldly go.
Usage Note: The split infinitive has been present in English ever since the 1300s, but it was not until the 1800s that grammarians labeled and condemned the usage. The only rationale for condemning the construction is based on a false analogy with Latin. The thinking is that because the Latin infinitive is a single word, the equivalent English construction should be treated as if it were a single unit. But English is not Latin, and distinguished writers have split infinitives without giving it a thought. Noteworthy splitters include John Donne, Daniel Defoe, George Eliot, Benjamin Franklin, Abraham Lincoln, William Wordsworth, and Willa Cather. Still, those who dislike the construction can usually avoid it without difficulty. The sense of the sentence To better understand the miners' plight, he went to live in their district is just as easily expressed by To understand the miners' plight better, he went to live in their district. However, one must take care not to ruin the rhythm of the sentence or create an unintended meaning by displacing an adverb. In general, the Usage Panel accepts the split infinitive. In our 2005 survey, 70 percent accepted the sentence The move allowed the company to legally pay the employees severance payments (acceptable to only 50 percent in 1988), and 91 percent accepted We expect our output to more than double this year. When the split in the infinitive gets wider, acceptance is more grudging. In 2005, 58 percent accepted We are seeking a plan to gradually, systematically, and economically relieve the burden. Back in 1988, only 23 percent accepted the same sentence. · Infinitive phrases in which the adverb precedes a participle, such as to be rapidly rising, to be clearly understood, and to have been ruefully mistaken, are not split and should be acceptable to everybody. By the same token, there are no grounds for objecting to the position of the adverb in the sentence He is committed to laboriously assembling all of the facts of the case. What is "split" here is not an infinitive but a prepositional phrase.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.