The Basics of the Infinitive｜How to Use “to + Base Verb” with Examples

In English, when I want to express ideas such as “to do something” or “in order to do something,” I use the infinitive (to + base verb). The infinitive is a flexible structure that can function like a noun, adjective, or adverb.

In this lesson, I will explain the basic uses of the infinitive and the key points for expressing meanings such as “to do” or “in order to do.”

1. The Basics of the Infinitive (to + Base Verb)

The infinitive is used in the form “to + base verb” and functions as a noun, adjective, or adverb within a sentence.

Whenever I want to say “to do something” or “in order to do something” in English, I use the infinitive.

The infinitive has three main functions:

Since the meaning changes depending on the context, it is important to be aware of what role the infinitive is playing in the sentence.

2. Noun Use: “to do something”

When used as a noun, the infinitive can function as the subject, object, or complement of a sentence.

2-1. As the subject

Here, “to travel alone” serves as the subject and indicates “what is exciting.”

2-2. As the object

Here, “to eat” is the object of the verb want, expressing “what I want to do.”

2-3. As the complement

In this example, “to become a singer” is the complement, providing an explanation of the subject.

3. Adjective Use: “for doing” / “to be done”

When an infinitive modifies a noun, it functions as an adjective.

In this usage, “to + verb” is placed after the noun and gives meanings such as “for doing” or “to be done.”

Here, “to do” modifies homework, adding the information “what kind of homework.”

This use is also common with words such as something / anything / nothing / the first / the last.

Here, something is an indefinite noun, and to drink specifies what kind of “something” it is.

4. Adverb Use: “in order to” / “so as to”

When an infinitive modifies a verb, adjective, or adverb, it provides additional information such as purpose, reason, result, or condition.

4-1. Purpose

Here, “to pass the exam” explains the purpose of studying.

4-2. Reason or grounds for judgment

Here, “to see you” explains the reason for the feeling of happiness.

Thus, the adverbial infinitive clarifies background or intention by answering questions such as “for what purpose,” “why,” or “how.”

5. Common Verbs and Expressions Used with the Infinitive

The infinitive is often used as the object of certain verbs. Some common examples are:

Some verbs (enjoy, finish, avoid, etc.) take a gerund (-ing form) instead of the infinitive, so it is important to distinguish between the two.

6. Summary

Izumi

Author

「English Morning｜基礎から学ぶ英語講座」を運営している泉（Izumi）です。このサイトでは基礎から応用まで、英語の文法を解説しています。