Just when we thought we had verbs figured out, we’re brought face-to-face with a new animal: non-finite verbs. These words look similar to verbs we’ve already discussed, but they act quite differently.

By definition, non-finite verbs cannot serve as the main verb in an independent clause. In practical terms, this means that they don’t provide the action of a sentence. They also lack 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. They can be created using active or helping verbs:

• I like swimming.
• Being loved can make someone feel safe.
• Do you fancy going out?
• 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, behave like 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 Complex 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. Below is a short list of some of the most common irregular past participles:

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 (which we’ll talk about in Complex Verb Tenses): The chicken has eaten. It is also used to form the passive voice: Tianna was voted most likely to succeed. When the passive voice is used following a relative pronoun (like that or which) we sometimes leave out parts of the phrase:

• He had three things that were taken away from him
• He had three things taken away from him

In the second sentence, we removed the words that were. However, we still use the past participle taken. The removal of these words is called elision. Elision is used with a lot of different constructions in English; we use it to shorten sentences when things are understood. However, we can only use elision in certain situations, so be careful when removing words! (We’ll discuss this further in Using the Passive Voice.)

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 are 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?

Historically, 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” (vs. “to go boldly”). Despite what a lot of people have asserted over the years, there is absolutely nothing wrong with this construction. It is 100 percent grammatically sound.

Part of the reason so many authorities have been against this construction is likely the fact that in languages such as Latin, the infinitive is a single word, and cannot be split. However, in English, the infinitive (or at least the to-infinitive) is two words, and a split infinitive is a perfectly natural construction.

The Bare Infinitive

As we mentioned, 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 be considered infinitives:

• 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.

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 as “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. Consider the following sentences:

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

In both 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 whether the verb should change:

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

Now that we’ve learned how to use each of the different non-finite verbs, let’s take a look at how they’re used together. The following practice will help you distinguish non-finite verbs from one another (and also distinguish them from the “normal” verbs we learned about earlier).