Should you say I enjoy to swim or I enjoy swimming? She decided to leave or She decided leaving? These choices confuse many English learners.
The answer depends on gerunds and infinitives. A gerund is a verb + -ing used like a noun (swimming). An infinitive is to + base verb (to swim). Some verbs are followed by a gerund, some by an infinitive, and some by both.
This guide explains the rules simply, with verb lists, examples and a short practice exercise.
What Is a Gerund?
A gerund looks like a present participle (-ing form), but it works as a noun. It can be:
- The subject: Reading is my hobby.
- The object: I love reading.
- After a preposition: She is good at reading.
What Is an Infinitive?
An infinitive is the base form of a verb, usually with to. It can be:
- The object: I want to read.
- To show purpose: I went to the library to read.
- After adjectives: It is easy to read.
Some infinitives appear without to, called the bare infinitive, for example after modal verbs (I can read) and after make and let (She made me laugh). The Cambridge Grammar page on infinitives with and without to explains these cases in detail.
Rule 1: Gerund as Subject
When a verb is the subject of a sentence, we usually use a gerund.
- Swimming is good exercise.
- Learning English takes time.
- Smoking is harmful to health.
An infinitive as subject (To swim is good exercise) is correct but sounds formal and old-fashioned.
Rule 2: Gerund After Prepositions
After a preposition, always use a gerund, never an infinitive.
- She is interested in learning French.
- Thank you for helping me.
- He left without saying goodbye.
- I am looking forward to meeting you.
Watch out: in look forward to, used to (be accustomed) and object to, the word to is a preposition, so a gerund follows: I am used to waking up early.
Rule 3: Verbs Followed by a Gerund
These common verbs are followed by a gerund:
admit, avoid, consider, delay, deny, dislike, enjoy, finish, give up, imagine, keep, mind, miss, postpone, practise, quit, recommend, risk, suggest.
- I enjoy playing cricket.
- She finished writing her essay.
- Would you mind closing the window?
- He suggested going to the beach.
- Avoid eating too much sugar.
Rule 4: Verbs Followed by an Infinitive
These common verbs are followed by an infinitive:
afford, agree, appear, arrange, ask, decide, deserve, expect, fail, hope, learn, manage, offer, plan, pretend, promise, refuse, seem, tend, want, wish, would like.
- I want to become a doctor.
- They decided to stay at home.
- She promised to call me.
- We can’t afford to buy a car.
- He refused to answer.
Rule 5: Verbs Followed by Object + Infinitive
Some verbs need an object before the infinitive:
advise, allow, ask, encourage, expect, force, invite, order, remind, teach, tell, want, warn.
- The teacher told us to be quiet.
- My parents encouraged me to study abroad.
- She reminded him to lock the door.
Rule 6: Verbs Followed by Both (Same Meaning)
With some verbs, both forms are possible with little or no change in meaning:
begin, start, continue, like, love, hate, prefer.
- It started raining. = It started to rain.
- I like reading. = I like to read.
Rule 7: Verbs Followed by Both (Different Meaning)
This is the trickiest group. The meaning changes depending on the form.
| Verb | + Gerund | + Infinitive |
|---|---|---|
| stop | He stopped smoking. (He quit.) | He stopped to smoke. (He paused in order to smoke.) |
| remember | I remember locking the door. (I locked it and I recall it.) | Remember to lock the door. (Don’t forget to do it.) |
| forget | I’ll never forget visiting Sajek. (memory of the past) | Don’t forget to bring your ID. (a future task) |
| try | Try drinking warm water. (as an experiment) | I tried to open the jar. (made an effort) |
| regret | I regret saying that. (I’m sorry I said it.) | We regret to inform you… (formal bad news) |
Rule 8: Infinitive to Show Purpose
Use an infinitive to explain why someone does something.
- I went to the market to buy vegetables.
- She saved money to buy a laptop.
Do not say for buy or for to buy.
Rule 9: Infinitive After Adjectives
- It is important to drink water.
- I was happy to see her.
- This question is difficult to answer.
Common Mistakes
| Wrong | Right |
|---|---|
| I enjoy to watch films. | I enjoy watching films. |
| She decided going home. | She decided to go home. |
| I look forward to see you. | I look forward to seeing you. |
| He went there for meet his friend. | He went there to meet his friend. |
| Let me to help you. | Let me help you. |
Practice Exercise
Choose the gerund or infinitive form of the verb in brackets.
- I hope ___ (pass) the exam.
- She avoided ___ (talk) to him.
- He is good at ___ (draw).
- They agreed ___ (help) us.
- Please remember ___ (send) the email.
- I stopped ___ (eat) fast food last year.
- My father made me ___ (clean) my room.
Answers: 1. to pass, 2. talking, 3. drawing, 4. to help, 5. to send, 6. eating, 7. clean
For more practice, try the Purdue OWL grammar exercises or the British Council B1–B2 grammar lessons.
Tips to Remember
- Learn verbs in groups: “enjoy, finish, avoid, mind + -ing” and “want, decide, hope, promise + to”.
- After any preposition, use -ing.
- For purpose, use to + verb.
- Write your own example sentence for each verb you learn.
Frequently Asked Questions
What is the difference between a gerund and an infinitive?
A gerund is the -ing form used as a noun (swimming). An infinitive is to + base verb (to swim).
Is “like” followed by a gerund or infinitive?
Both are correct: I like swimming and I like to swim. But would like always takes an infinitive: I would like to swim.
Why is it “look forward to seeing”?
Because to here is a preposition, and prepositions are followed by gerunds.
Conclusion
Gerunds and infinitives follow patterns you can learn. Use gerunds as subjects and after prepositions; use infinitives for purpose and after many verbs like want and decide. Learn the special verbs like stop and remember where meaning changes.
For deeper study, see our reviews of Practical English Usage by Michael Swan, Advanced Grammar in Use, and A Comprehensive Grammar of the English Language.
