What is the ‘To + Infinitive’ Form?

The infinitive is the basic form of a verb. For example, go, eat, study.

The ‘to + infinitive’ form means you add to before the base verb. This is the form you often see in dictionaries.

• Examples: to go, to eat, to study.

To make it negative, simply put not 以前 to.

• Examples: not to go, not to eat, not to study.

How Do We Use 'To + Infinitive' for Purpose?

当社では to + infinitive to explain why you do something. It shows the reason or purpose for an action.

Think of it like answering the question 'Why?'.

• I went to the shop to buy some milk. (Why did I go? To buy milk.)
• She studies hard to pass her exams. (Why does she study? To pass her exams.)

Which Verbs Are Followed by 'To + Infinitive'?

Many verbs in English are directly followed by to + infinitive. You need to learn these common patterns.

Here are some frequent verbs that take to + infinitive:

• choose, decide, want, would like, try, promise, expect, remember, forget, need, plan, learn, offer.

These verbs often express desires, intentions, or future actions.

When Do We Use 'To + Infinitive' After Adjectives?

You can often use to + infinitive after many adjectives. This structure describes 何 the adjective refers to or why someone feels a certain way.

Common adjectives include: happy, sad, easy, difficult, important, surprised, glad.

'To + Infinitive' with Question Words

Some verbs can be followed by a question word (what, where, how, who, when, which) and then to + infinitive.

This structure helps to ask or explain how to do something, 何 to do, etc.

Common verbs for this pattern include: ask, decide, explain, forget, know, show, tell, understand.

例

• I want to learn English.
• They decided to travel next year.
• He promised not to be late.
• It's important to study every day.
• I was happy to see you.
• This problem is difficult to solve.
• I don't know what to do.
• Can you tell me where to go?
• She showed me how to use the machine.

練習

スペイン語話者がよく犯す間違い

1. Using 'for + -ing' instead of 'to + infinitive' for purpose.

Spanish speakers often translate 'para' directly, leading to this common error. In English, to express purpose, we use to + infinitive.

• 誤り： I went to the library for studying.
• 正しい： I went to the library to study.

2. Using a gerund (-ing) after verbs that require 'to + infinitive'.

Certain verbs must be followed by to + infinitive, not the -ing form. Always check which form a verb takes.

• 誤り： I want going home.
• 正しい： I want to go home.
• 誤り： She decided travelling.
• 正しい： She decided to travel.

よくある質問

What is the main difference between 'to + infinitive' and the gerund (-ing form)?

Generally, to + infinitive often expresses purpose, future actions, or intentions. The gerund often refers to general activities, completed actions, or follows prepositions. For example, I like to swim (an activity I enjoy doing) versus I like swimming (the general activity of swimming). Some verbs can take both with a change in meaning.

Can I use 'to + infinitive' to talk about future plans?

Yes, absolutely! Many verbs related to planning and future intentions are followed by to + infinitive. For instance, I plan to visit my family next month または She hopes to start a new job soon.

Is 'to + infinitive' common in formal or informal English?

To + infinitive is very common in both formal and informal English. It's a fundamental grammatical structure used in everyday conversation and academic writing alike.

How can I remember which verbs take 'to + infinitive'?

The best way is through practice and exposure. Read a lot, listen to English, and pay attention to these patterns. You can also group verbs by meaning (e.g., verbs of desire: want to, hope to, wish to; verbs of planning: plan to, decide to). Consistent practice will help you remember.

関連レッスン

• Gerunds and infinitives
• Gerunds and infinitives