Finite and Non-finite Verbs
What is a finite verb?
Finite verbs are verbs that have subjects and indicate grammatical tense, person, and number. These verbs describe the action of a person, place, or thing in the sentence. Unlike other types of verbs, finite verbs do not require another verb in the sentence in order to be grammatically correct.
Here are some examples of finite verbs:
- “They went to the mall today.”
- “The outfielder leaped for the baseball.”
- “Many people travel to the ocean in the summer.”
- “The sailboat glides over the water.”
- “The lion is the king of the jungle.”
What is a non-finite verb?
Non-finite verbs are verbs that do not have tenses or subjects that they correspond to. Instead, these verbs are usually infinitives, gerunds, or participles. Gerunds and present participles end in “-ing,” while past participles usually end in “-ed,” “-d,” or “-t.”
Let’s have a look at how infinitives, gerunds, and participles (in italics) function in a sentence in contrast to finite verbs (in bold).
If an infinitive is used in its full form (to + base form of the verb), it can function as a noun, adjective, or adverb in the sentence. Bare infinitives (base form of the verb without to) of non-finite verbs are used in conjunction with modal auxiliary verbs, which are considered the finite verb(s) of the sentence. For example:
- “To run is often tiresome.” (The infinitive to run functions as a noun, while is functions as the finite verb.)
- “I have a suggestion to help you study.” (The phrase to help you study functions as an adjective, modifying the noun suggestion; the verb have is the finite verb.)
- “I can’t swim yet.” (The bare infinitive swim relies on the finite auxiliary verb can to be complete, so it is non-finite in this sentence.)
Gerunds are “-ing” forms of a verb that function as nouns in a sentence. Because they do not have the grammatical function of a verb, gerunds are always non-finite.
- “Seeing the ocean for the first time is incredible.”
- “Reading books is often very enjoyable.”
Present participles have the same form as gerunds, ending in “-ing.” However, they function in a sentence as either part of a continuous tense, relying on an auxiliary verb to be complete; as an adjunct to a finite verb, indicating a secondary action; or as an attributive or predicative adjective, modifying a noun.
- “My daughter is watching me work.” (Watching is used with is to form the present continuous tense.)
- “The car sat rusting in the driveway for over a year.” (Rusting is used in conjunction with the finite verb sat to indicate a parallel activity.)
- “I read a very engaging book last week.” (Engaging functions as an attributive adjective of book.)
- “This book is engaging.” (Engaging functions as a predicative adjective, following the finite linking verb is and modifying book.)
It is important to note that non-finite past participles and finite past tense verbs often both end in “-d” or “-ed.” If the word directly describes the action of a subject, then it is a finite verb. However, if the word is being used as an adjective or requires another verb to be complete, then it is a non-finite verb.
- “I had already walked for many miles.” (Walked is a past participle that depends on the auxiliary verb have to create the past perfect tense.)
- “Those clothes are washed.” (Washed is a past participle acting as an predicative adjective to the noun clothes, following the finite linking verb are.)
- “She carried the washed clothes upstairs.” (Carried is a past tense verb describing the action of the subject, she; washed is a past participle acting as an attributive adjective to the noun clothes.)
Importance to sentence structure
Sentences need a finite verb in order to be complete. Without a finite verb, a sentence would simply be a subject, or a subject and other parts of speech that do not express action and are not linked together properly. In other words, sentences do not function correctly without finite verbs.
To illustrate this point, consider the following examples:
- “The car.”
- “The car on the road.“
- “The car on the road through the mountains.”
In the above examples, car is the subject. In order to make complete sentences, a finite verb must be used to describe the action of the car, as well as to show how the other parts of the sentence relate to it. In the following examples, a finite verb is used to form complete sentences:
- “The car drove.”
- “The car drove on the road.”
- “The car drove on the road through the mountains.”
Simply adding the finite verb drove makes all three of these sentences complete. This is because it lets the reader know what the car is doing, and it connects the subject to the other parts of the sentence.
We can also see how a using a non-finite verb instead of a finite one would render the sentence incomplete again. For example:
- “The car driving on the road through the mountains.”
Because we used the present participle driving, the sentence is now disjointed—the action is not fully expressed by the sentence. We would need to add a finite verb to complete it, as in:
- “The car was driving on the road through the mountains.”
Identifying finite verbs
Due to the fact that multiple types of verbs can often exist in the same sentence, it is helpful to know some common instances of finite verbs that can help you identify them.
Third person singular present verbs ending in “-s”
Any verb that has an “-s” ending for the third person singular present form is a finite verb. Non-finite verbs do not have tense, and thus never switch their endings to “-s” in the third person singular present form.
(The exceptions to this are modal auxiliary verbs: can, could, will, would, shall, should, may, might, and must. Modal verbs also cannot take an “-s” ending for third person singular present; however, they are always finite. They come directly after the subject and before main verbs, and help to determine aspect, tense, and mood.)
Here are some examples of finite verbs in the third person singular present form with “-s” endings:
- “He runs to the store every morning.”
- “The woman swims in the ocean.”
- “The boy kicks the soccer ball at the goal.”
- “She has three cars in her driveway.”
Past-tense irregular verbs
Verbs that are functioning in the past tense (not past participles) are inherently finite. As we noted above, the majority of verbs have the same form for both past tense and past participle. These are known as regular verbs. To determine if a regular verb is in the past tense or is a past participle (and thus finite or non-finite), we have to examine how it is functioning in the sentence.
However, some verbs are irregular, and they have a past tense form that is separate from their past participle form. Here are a few examples of sentences using irregular verbs:
- “She was feeling unwell.” (past tense – finite)
- “She has been feeling unwell.” (past participle – non-finite)
- “I went to the store.” (past tense – finite)
- “I had gone to the store.” (past participle – non-finite)
- “They flew to San Diego already.” (past tense – finite)
- “They have flown to San Diego already.” (past participle – non-finite)
There are quite a few irregular verbs, and there is no rule to how they are conjugated (which is why they are irregular). To learn more, go to the section about Regular and Irregular Verbs.
Verbs that immediately follow subjects
Finite verbs often directly follow the subjects whose actions they are describing. This location allows for a clear connection between the subject and the verb—it makes it easy for the reader or listener to understand that the verb is describing the action of the subject and not another word in the sentence. Here are some examples of finite verbs appearing directly after subjects in sentences:
- “Everyone listened to the music.”
- “Elephants travel together in herds to find water.”
- “Across the field, the trees swayed in the wind.”
Non-finite verbs, however, generally do not appear directly after the subject. This is because they are often not directly describing the action of the subject, but are instead serving another grammatical purpose in the sentence.