split infinitive

1 7.2

A phrase where a word like 'boldly' comes between to and a verb, as in 'to boldly go'

noun
/splɪt ˌɪn.fɪˈnɪ.tɪv/

Specialized

: infinitivo partido

Here also was the origin of the prohibition on splitting infinitives.

Examples

Despite the split infinitive, which bugged Hershel, we nodded and sat down along with Mom, all waiting for the new Sergeant York.

Fiction book (1994)
Oh, there's a split infinitive here in the second paragraph.

Quiz Show (1994)
One common example of a split infinitive is ‘to boldly go’ from the famous TV show.
Many writers avoid using a split infinitive in their sentences to maintain traditional grammar.
In modern English, using a split infinitive is considered acceptable by many grammar experts.

Surface Forms

split infinitive singular

split infinitives plural

Morphology

split + infinitive

The phrase transparently combines 'split' (to divide or put something between) with 'infinitive' (the to+verb form), so a learner can infer it denotes an infinitive that has been divided by inserting another word (e.g. 'to boldly go'). Although a grammatical/technical label, the composition is literal and directly derivable from the constituents, making the concept inferable for someone who knows both words.

Etymology

The term split infinitive comes from old grammar rules that thought to and the verb were one piece, so putting a word between them looked like 'splitting' it. So the example 'to boldly go' has the adverb 'boldly' between to and the verb, and that is why the phrase is called a split infinitive today.