Split Infinitive

exploring the cases of split infinitive

As pointed out in the concluding part of the INFINITIVE studyOpens in new window, a word shouldn’t come in between the infinitive. But sometimes a word usually an adverb or phrase would manage to sneak in between an infinitive, giving room to what is called SPLIT INFINITIVE. Within this study, we’ll take adventure into the realm of Split Infinitives.
  • A SPLIT INFINITIVE (also called CLEFT INFINITIVE) is a grammatical construction in which a word or phrase comes between the to and the bare infinitive of the to form of the infinitive verb. Usually, an adverb or an adverbial phrase comes between them.

A viral split infinitive in recent years comes from the famous quote from Star TrekOpens in new window: “To boldly go where no man has gone before.”

    which could have been written as,
  • To go boldly where no man has gone before.

It is a good principle to avoid sneaking words into infinitives, the argument being that infinitive is a single unit and, therefore should not be divided.

Although, a purposefully split infinitive may be preferred in some cases. For example, consider the phrase “to promote exercise vigorously” (Iverson et al., 1998).

There could be confusion by some as to whether vigorously relates to promote or exercise, hence writing “to vigorously promote exercise” could be clearer, unless of course the intent was “to promote vigorous exercise.”

Nevertheless, the general rule should be: Do not split infinitives unless the sentence is less awkward when doing so.

Examples of Split Infinitives are shown in the table below. Accompanied on the right are its respective corrections.

Split InfinitivesThe preferred Infinitives
  • The goal of this project is to better understand
  • The goal of this project is to understand better…
  • We plan to quickly initiate the funded study.
We plan to initiate the funded study quickly.
  • It is difficult to separately Control X and Y…
  • It is difficult to control X and Y separately
  • It is bad practice in the laboratory to arbitrarily stop an experiment.
  • It is bad practice in the laboratory to stop an experiment arbitrarily.
  • To effectively study the source of the error.
To study the source of the error Effectively.
  • The sponsor requested us to, with all possible haste, complete the final report.
  • The sponsor requested us to complete the final report with all possible haste.
The last example in the table is a particularly flagrant abuse of the infinitive.

Other examples of split infinitives occur when a single “to” serves multiple infinitives.

    Whereas it is generally acceptable to write,
  • “There is a need to assemble and test the device,”
  • rather than
  • “There is a need to assemble and to test the device.”

Finally, note that infinitives can occur in active or passive voice and in past or present tense. In such cases, the infinitives may take different forms, such as:

Present activeto tell
Present passiveto be told
Past activeto have told
Past passiveto have been told
Important! 

The Oxford American Desk Dictionary, which came out in October of 1998, says that the rule against the split infinitive can generally be ignored, that the rule “is not firmly grounded, and treating two English words as one can lead to awkward, stilted sentences.” (“To Boldly Go,” The Hartford Courant. 15 Oct 1998.)

Opinion among English instructors and others who feel strongly about the language remains divided, however. Today's dictionaries allow us to split the infinitive, but it should never be done at the expense of grace.

The Bare Infinitive

In the previous studyOpens in new window, we made mention of the bare infinitive—an infinitive without the particle to. However, verbs of perception such as “hear,” “see,” “watch,” “feel,” etc. and a handful of other verbs i.e., “help,”, “let,” and “make,” usually take the bare infinitive in the active voice, as exemplified in the following sentences.

  • We watched him clear the table.
  • They heard the thief crash through the door.
  • She made me do it.
  • We helped her finish the homework.

Forming statements with a negative infinitive

The negative infinitive is formed by adding not in front of any form of the infinitive.

  • We decided not to go back there.
  • She'll rather not sing.
  • Not to miss the class will be ideal.
  • Andy might not do it.
  • He went into business not to broke again.

Using the Infinitive with Question words

The verbs: ask, decide, explain, forget, know, show, tell, and understand can be followed by a question word such as where, how, what, who, and when + the infinitive marker, to.

Examples include:
  • She asked me how to use the gadget.
  • Do you understand what to do?
  • Tell me when to pull the lever.
  • I've forgotten where to look again.