Writers should avoid splitting an infinitive when: The sentence is already clear; It sounds awkward to split the infinitive; Too much information is inserted between the two parts of the infinitive. To split an infinitive is to put a word or words between the infinitive marker—the word to—and the root verb that follows it. Writers should avoid splitting an infinitive because it expresses a single idea (a unit of thought), and they must try to keep its two parts—the marker to and the root verb that follows it—together if they can. The writers´ job is to make the reader’s job easy like keeping logical units of thought intact. It would be an effort to make English grammar function in the same way that Latin grammar does: An infinitive is a single word and therefore cannot be split.
The infinitive is the form of the verb that has the "to" in front of it (does not function in sentences as verbs but rather as adverbs, adjectives, or nouns).
