|(in English grammar) an infinitive used with another word between to (the infinitive marker) and the verb itself, as in I want to really finish it this time|
|usage The traditional rule against placing an adverb between to and its verb is gradually disappearing. Although it is true that a split infinitive may result in a clumsy sentence (he decided to firmly and definitively deal with the problem), this is not enough to justify the absolute condemnation that this practice has attracted. Indeed, very often the most natural position of the adverb is between to and the verb (he decided to really try next time) and to change it would result in an artificial and awkward construction (he decided really to try next time). The current view is therefore that the split infinitive is not a grammatical error. Nevertheless, many writers prefer to avoid splitting infinitives in formal written English, since readers with a more traditional point of view are likely to interpret this type of construction as incorrect|
An infinitive is the “to” form of a verb, as in “to play.” A split infinitive is a phrase in which to is separated from the verb. The sentence “I decided to quickly and directly go home” contains a split infinitive. Some people consider it poor style, or even incorrect style, to split an infinitive.