Just when we thought we had verbs figured out, we’re brought face-to-face with a new animal: the non-finite verbs. These words look similar to verbs we’ve already been talking about, but they act quite different from those other verbs.

By definition, a non-finite verb cannot serve as the root of an independent clause. In practical terms, this means that they don’t serve as the action of a sentence. They also don’t have a tense. While the sentence around them may be past, present, or future tense, the non-finite verbs themselves are neutral. There are three types of non-finite verbs: gerunds, participles, and infinitives.

Gerunds

Gerunds all end in -ing: skiing, reading, dancing, singing, etc. Gerunds act like nouns and can serve as subjects or objects of sentences. Let’s take a look at a few examples:

• Swimming is fun.
• I like swimming.
• I never gave swimming all that much effort.
• Do you fancy going out?

Gerunds can be created using helping verbs as well:

• Being deceived can make someone feel angry.
• Having read the book once before makes me more prepared.

Often the “doer” of the gerund is clearly signaled:

• We enjoyed singing yesterday (we ourselves sang)
• Tomás likes eating apricots (Tomás himself eats apricots)

However, sometimes the “doer” must be overtly specified, typically in a position immediately before the non-finite verb:

• We enjoyed their singing.
• We were delighted at Bianca being awarded the prize.

Participles

A participle is a form of a verb that is used in a sentence to modify a noun, noun phrase, verb, or verb phrase, and then plays a role similar to an adjective or adverb. It is one of the types of nonfinite verb forms.

The two types of participle in English are traditionally called the present participle (forms such as writing, singing and raising) and the past participle (forms such as written, sung and raised).

The Present Participle

Even though they look exactly the same, gerunds and present participles do different things. As we just learned, the gerund acts as a noun: e.g., “I like sleeping“; “Sleeping is not allowed.” Present participles, on the other hand, act similarly to an adjective or adverb: e.g., “The sleeping girl over there is my sister”; “Breathing heavily, she finished the race in first place.”

The present participle, or participial phrases (clauses) formed from it, are used as follows:

• as an adjective phrase modifying a noun phrase: The man sitting over there is my uncle.
• adverbially, the subject being understood to be the same as that of the main clause: Looking at the plans, I gradually came to see where the problem lay. He shot the man, killing him.
• more generally as a clause or sentence modifier: Broadly speaking, the project was successful.

The present participle can also be used with the helping verb to be to form a type of present tense: Marta was sleeping. (We’ll discuss this further in Text: Advanced Verb Tenses.) This is something we learned a little bit about in helping verbs and tense. 

The Past Participle

Past participles often look very similar to the simple past tense of a verb: finished, danced, etc. However, some verbs have different forms. Reference lists will be your best help in finding the correct past participle. Here is one such list of participles. Here’s a short list of some of the most common irregular past participles you’ll use:

Past participles are used in a couple of different ways:

• as an adjective phrase: The chicken eaten by the children was contaminated.
• adverbially: Seen from this perspective, the problem presents no easy solution.
• in a nominative absolute construction, with a subject: The task finished, we returned home.

The past participle can also be used with the helping verb to have to form a type of past tense: The chicken has eaten. This is something we learned about in helping verbs and tense.

Infinitives

To be or not to be, that is the question.

—Hamlet

The infinitive is the basic dictionary form of a verb, usually preceded by to (when it’s not, it’s called the bare infinitive, which we’ll discuss more later). Thus to go is an infinitive. There are several different uses of the infinitive. They can be used alongside verbs, as a noun phrase, as a modifier, or in a question.

With Other Verbs

The to-infinitive is used with other verbs (we’ll discuss exceptions when we talk about the bare infinitive):

• I aim to convince him of our plan’s ingenuity.
• You already know that he’ll fail to complete the task.

You can also use multiple infinitives in a single sentence: “Today, I plan to run three miles, to clean my room, and to update my budget.” All three of these infinitives follow the verb plan. Other verbs that often come before infinitives include want, convince, try, able, and like.

As a Noun Phrase

The infinitive can also be used to express an action in an abstract, general way: “To err is human”; “To know me is to love me.” No one in particular is completing these actions. In these sentences, the infinitives act as the subjects.

Infinitives can also serve as the object of a sentence. One common construction involves a dummy subject (it): “It was nice to meet you.”

As a Modifier

Infinitives can be used as an adjective (e.g., “A request to see someone” or “The man to save us”) or as an adverb (e.g., “Keen to get on,” “Nice to listen to,” or “In order to win“).

In Questions

Infinitives can be used in elliptical questions as well, as in “I don’t know where to go.”

Split Infinitives?

One of the biggest controversies among grammarians and style writers has been the appropriateness of separating the two words of the to-infinitive as in “to boldly go.” Despite what a lot of people have declared over the years, there is absolutely nothing wrong with this construction. It is 100 percent grammatically sound.

The Bare Infinitive

As we mentioned previously, the infinitive can sometimes occur without the word to. The form without to is called the bare infinitive (the form with to is called the to-infinitive). In the following sentences both sit and to sit would each be considered an infinitive:

• I want to sit on the other chair.
• I can sit here all day.

Infinitives have a variety of uses in English. Certain contexts call for the to-infinitive form, and certain contexts call for the bare infinitive; they are not normally interchangeable, except in occasional instances like after the verb help, where either can be used.

As we mentioned earlier, some verbs require the bare infinitive instead of the to-infinitive:

• The helping verb do
  • Does she dance?
  • Zi doesn’t sing.
• Helping verbs that express tense, possibility, or ability like will, can, could, should, would, and might
  • The bears will eat you if they catch you.
  • Lucas and Gerardo might go to the dance.
  • You should give it a try.
• Verbs of perception, permission, or causation, such as see, watch, hear, make, let, and have (after a direct object)
  • Look at Caroline go!
  • You can’t make me talk.
  • It’s so hard to let someone else finish my work.

The bare infinitive can be used as the object in such sentences like “What you should do is make a list.” It can also be used after the word why to ask a question: “Why reveal it?”

The bare infinitive can be tricky, because it often looks exactly like the present tense of a verb. Look at the following sentences for an example:

• You lose things so often.
• You can lose things at the drop of a hat.

In both of these sentences, we have the word lose, but in the first sentence it’s a present tense verb, while in the second it’s a bare infinitive. So how can you tell which is which? The easiest way is to try changing the subject of the sentence and seeing if the verb should change:

• She loses things so often.
• She can lose things at the drop of a hat.