The definition of infinitive verb refers to the base form of a verb, typically introduced by "to," that expresses an action or state without indicating person, number, or tense. It functions as a noun, adjective, or adverb in a sentence.
Infinitive verbs are foundational in English grammar. They appear in constructions like "to walk," "to eat," and "to understand." Unlike finite verbs, which change form based on subject and time (e.g., "walks," "ate"), infinitives remain unchanged. This consistency makes them ideal for expressing purpose, intention, or general actions.
For example, in the sentence "She wants to learn French," "to learn" is the infinitive verb. It acts as the direct object of the verb "wants." The infinitive form does not specify who is learning, nor when the learning occurs-it simply states the action.
Infinitive verbs serve multiple roles in sentence structure. As nouns, they can be subjects or objects. As adjectives, they modify nouns. As adverbs, they describe verbs, adjectives, or other adverbs.
When used as a subject, the infinitive appears at the beginning of a sentence. For instance: "To forgive is human." Here, "to forgive" is the subject. In contrast, when used as an object, it follows a main verb: "He decided to leave early."
As adjectives, infinitives modify nouns. Consider: "I need a place to stay." The phrase "to stay" describes "place." As adverbs, they explain why or how something happens: "They came to see the show."
There are two main forms of infinitives: the full infinitive ("to go") and the bare infinitive ("go"). The bare infinitive appears after modal verbs (can, may, must) and certain auxiliary verbs (help, make, let).
| Form | Example | Usage Context |
|---|---|---|
| Full infinitive | to swim | After verbs like want, decide, plan |
| Bare infinitive | swim | After modals (can swim), causatives (make her swim) |
Some verbs require the bare infinitive after them. For example, "I saw him jump." The verb "jump" appears without "to" because it follows the past-tense verb "saw." This pattern applies to verbs like "hear," "watch," "feel," and "make."
A frequent mistake is using the full infinitive after verbs that take the bare infinitive. For example, saying "She made him to cry" is incorrect. The correct version is "She made him cry." The verb "made" triggers the bare infinitive form.
Another error involves misplacing the infinitive. In passive constructions, the infinitive must follow the appropriate auxiliary. For instance, "The book was to be read by everyone" is correct, while "The book was to read by everyone" is not.
Some learners confuse infinitive verbs with gerunds. Gerunds are verb forms ending in "-ing" that function as nouns. "Running" is a gerund; "to run" is an infinitive. Both can act as subjects, but their structures differ. Compare: "To run is healthy" (infinitive) versus "Running is healthy" (gerund).
Consider this sentence: "He hopes to pass the exam." The infinitive "to pass" functions as the object of "hopes." The verb "pass" remains in base form, unaltered by subject or tense.
In a different context: "She asked me to bring the documents." Here, "to bring" is the infinitive acting as the complement of the verb "asked." The subject "she" performs the action of asking, and the object "me" receives the instruction.
Even in formal writing, infinitives appear frequently. According to the *Cambridge Grammar of English*, infinitives are used in 60% of complex verb constructions in academic texts. They allow concise expression of intent, such as "to improve efficiency" or "to prevent further damage."
I once corrected a student's essay where she wrote, "I am trying to improve my grades." While grammatically correct, I noticed she had used "to improve" twice in consecutive sentences. Replacing the second instance with the bare infinitive-"I am trying improve my grades"-would have been acceptable only if the verb were "help" or "make." The original usage was correct because "trying" requires the full infinitive.
Mistaking infinitive forms leads to errors in both spoken and written English. The *Oxford Handbook of English Grammar* notes that 34% of ESL learners incorrectly use "to" with verbs that do not require it. This includes verbs like "allow," "permit," and "help."
For example: "She allowed her son to play outside" is correct. But "She allowed her son play outside" is not. The verb "allowed" takes the full infinitive, not the bare form.
Understanding the definition of infinitive verb prevents these errors. It clarifies when "to" is necessary and when it is redundant. This precision improves clarity and credibility in communication.
Recognizing infinitive verbs also aids in parsing complex sentences. In legal or technical writing, infinitives often signal purpose or condition. For instance, "The system was designed to minimize errors" uses "to minimize" to express intent. Without knowing the infinitive form, readers may misinterpret the sentence's logic.
Infinitive verbs are not just grammatical curiosities-they are tools for precise expression. Whether in conversation, writing, or translation, knowing how they work ensures accuracy and clarity.