The Grammarphobia Blog

Is “to” part of the infinitive?

Q: In your recent article for Smithsonian magazine, you defend the split infinitive by saying “to” isn’t actually part of the infinitive. Huh? Says who? Not any standard – or even nonstandard – grammar book or authority I’ve ever seen, heard of, or read. Here’s the standard definition of an infinitive, from Warriner’s English Grammar and Composition: “An infinitive is a verbal consisting of to followed by the verb.”

A: Sorry, but you’ve been misled, and the late John Warriner, a teacher and textbook author, was misinformed, as we’ll explain. His is absolutely NOT the “standard” definition of an infinitive.

The infinitive is the uninflected or basic form of a verb, and “to” is not part of it. When “to” appears with an infinitive, it is generally referred to as an “infinitive marker” or “infinitive particle”; it is not part of the verb and is not always used.

“To” is not there, for example, when the infinitive is used with modal verbs (sometimes called modal auxiliaries or secondary auxiliaries). The modal verbs are “can,” “could,” “may,” “might,” “shall,” “should,” “will,” “would,” and “must.”

Examples, “I must go,” “he should read,” “they can eat,” and so on. In modal constructions, infinitives (”go,” “read,” and “eat” in the examples) do not require “to.”

You don’t have to take our word for this. We can cite a great many authorities. Here are only a few.

(1) Fowler’s Modern English Usage (rev. 3rd ed.), edited by the language scholar and lexicographer R. W. Burchfield, likewise describes two uses of the infinitive: (a) “the to-infinitive,” in which “to” is described as a “particle,” and (b) “the bare or simple or plain infinitive.”

The bare infinitive, Fowler’s says, “is often optionally used after the verbs dare, help, and need.” (Examples of infinitives used this way would be, “Does he dare go?” “We helped them move,” “You need not come.” Here, “go,” “move,” and “come” are infinitives.)

Fowler’s adds: “But its use after modal verbs (can, may, must, shall, etc.) and after comparatives and superlatives (better, had better, best, had best, rather than, etc.) is much more significant.” (For example, in constructions like “we had better eat,” and “rather than eat later,” the verb “eat” is an infinitive.)

Fowler’s also mentions these other common uses of the bare infinitive:

(a) At the head of a clause, as in “Try as I might, I couldn’t … etc.” Here, “try” is an infinitive.

(b) After “let” plus its object, as in “Let him enjoy his ignorance.” Here, “enjoy” is an infinitive.

(c) After “is” and “was,” as in “All they want to do is hide in the kitchen.” Here, “hide” is an infinitive.

(d) After “why” and “why not,” as in “Why not ask Robert?” Here, “ask” is an infinitive.

Some other sources:

(2) The Cambridge Grammar of the English Language says the infinitive (as well as the imperative and the subjunctive) “consists simply of the lexical base, the plain base without any suffix or other modification.” (Examples of imperative and subjunctive forms of “run,” respectively would be: “Run as fast as you can!” and “I suggest you run.”)

The Cambridge Grammar, written by the linguists Geoffrey Pullum and Rodney Huddleston, goes on to explain that the marker “to” is “not part of the verb.”

 “The traditional practice for citation of verbs is to cite them with the infinitival marker to, as in ‘to be,’ ‘to take,’ and so on,” Cambridge continues. “That is an unsatisfactory convention, because the to is not part of the verb itself.”

The word “to” here “is not a (morphological) prefix but a quite separate (syntactic) word,” Pullum and Huddleston say, adding:

“This is evident from the fact that it can stand alone in elliptical constructions (as in I haven’t read it yet, but I hope to shortly), need not be repeated in coordination (as seen in I want to go out and get some exercise), and can be separated from the verb by an adverb, as seen in the so-called ‘split infinitive construction,’ I’m trying to gradually improve my game.”

(3) The Oxford English Grammar, written by the linguist Sidney Greenbaum, says the infinitive “has two major uses: (a) bare infinitive (without to) follows a modal auxiliary, [as in] ‘I must write that message’; (b) to-infinitive is the main verb in infinitive clauses [as in] ‘I’d like to write something on process theology.’ ”

Even dictionaries don’t use Warriner’s definition. Witness:

(4) The American Heritage Dictionary of the English Language (5th ed.), definition of “infinitive”: “A verb form that functions as a substantive while retaining certain verbal characteristics, such as modification by adverbs, and that in English may be preceded by to, as in To go willingly is to show strength or We want him to work harder, or may also occur without to, as in She had them read the letter or We may finish today.

(5) Merriam-Webster’s International, Unabridged Third Edition, definition of “infinitive”: “an infinite verb form normally identical in English with the first person singular that performs certain functions of a noun and at the same time displays certain characteristics (as association with objects and adverbial modifiers) of a verb and is used with to (as in ‘to err is human’; ‘I asked him to go’) except with auxiliary and certain other verbs (as in ‘he can see’; ‘let me go’; ‘no one saw him leave’).

(6 ) The Oxford English Dictionary has an extensive discussion of the historical development of “to” with the infinitive in Old and Middle English. Later it has this: “The simple infinitive, without to, remains: 1. after the auxiliaries of tense, mood, periphrasis, shall, will; may, can; do; and the quasi-auxiliaries, must, (and sometimes) need, dare: 2. after some vbs. of causing, etc.; make, bid, let, have, in sense B. 15a; 3. after some vbs. of perception, see, hear, feel, and some tenses of know, observe, notice, perceive, etc., in sense B. 15b; 4. after had liefer, rather, better, sooner, as lief, as soon, as good, as well, etc.: see have v. 21, rather adv. 8d, and the other words.

“The infinitive with to may be dependent on an adj., a n., or a vb., or it may stand independently. To an adj. it stands in adverbial relation: ready to fight = ready for fighting; to a n. it stands in adjectival or sometimes adverbial relation: a day to remember = a memorable day; to a vb. it may stand in an adverbial or substantival relation: to proceed to work = to proceed to working; to like to work = to like working.”

When this preposition was first used in English as an infinitive marker ( in Old English), it did have a prepositional flavor. “I prepared to eat” sounded to the medieval ear something like “I prepared for eating”; “he fails to think” sounded something like “he fails in thinking”; “we strive to please” sounded something like “we strive toward pleasing.” As the OED says, “it expressed motion, direction, inclination, purpose, etc., toward the act or condition expressed by the infinitive; as in ‘he came to help (i.e. to the help of) his friends,’ … ‘he prepared to depart (i.e. for departure).’ ”

There once was a sense of motion, of moving toward accomplishing something (represented by the infinitive), if that makes any sense.

But as the OED says: “in process of time this obvious sense of the prep. became weakened and generalized, so that became at last the ordinary link expressing any prepositional relation in which an infinitive stands to a preceding verb, adjective, or substantive.” [Here the italicized represents the Old English word.]

As we’ve written on our blog, a great many people misunderstand infinitives because they aren’t familiar with their many uses.

In that post, we cite the clause “I saw her fall,” with the verb “fall” in the infinitive. In English, this is a very common pattern: one verb followed by a second in the infinitive. It’s often the case when the first verb is one involving sensory perception (“see,” “feel,” “hear”).

Here are a few examples of the kinds of verbs that are often paired with infinitives (the infinitives are underlined):

“I helped her walk” … “They saw us go” … “We felt it move” … “He heard her cry” … “You need not worry” … “Dare we ask?” … “I would rather die” … “We will let it rest” … “Let there be light.”

In addition, the auxiliary “do” is often used with an infinitive to form a question: “Do you smoke?” … “Did they drive?”

And as we’ve said, the modal auxiliary verbs (“can,” “may,” “must,” etc.) take infinitives as their complements: “She may smoke” [or “May she smoke?”] … “We must leave” [or “Must we leave?”].

In all of these cases, the second verb is in the infinitive. But many people don’t recognize these verb forms as infinitives because they expect infinitives to be preceded by “to.” As you can see, that’s often not the case.

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