The quick rule: use a gerund (the -ing form) after certain verbs such as enjoy, avoid, finish and consider, and after every preposition; use an infinitive (to + verb) after verbs such as want, decide, hope and agree, and after adjectives. A handful of verbs — begin, like, hate — take either form with no real change, while a few — remember, stop, try, forget — change meaning depending on which you choose.
Gerund vs infinitive: what's the difference?
A gerund is the -ing form of a verb used as a noun: swimming, reading, working. It looks identical to the present participle in I am swimming, but it does the job of a noun. An infinitive is to plus the base verb: to swim, to read, to work. Both can serve as the subject or object of a sentence, which is exactly why they so often compete for the same slot.
- Gerund as subject: Swimming keeps me fit.
- Infinitive as subject: To swim the Channel takes months of training.
- Gerund as object: I enjoy swimming.
- Infinitive as object: I want to swim.
The difficulty begins when one verb follows another. English won't let you choose freely — the first verb dictates the form of the second, and you simply have to know which verbs demand which.
Verbs followed by a gerund (-ing)
These verbs take the -ing form. The common ones include enjoy, avoid, finish, mind, suggest, consider, admit, deny, imagine, keep, miss, postpone, practice, recommend, risk, can't stand and can't help.
- ✓ I enjoy cooking. — ✗ I enjoy to cook.
- ✓ She avoided answering the question. — ✗ She avoided to answer the question.
- ✓ Have you finished eating? — ✗ Have you finished to eat?
- ✓ I don't mind waiting. — ✗ I don't mind to wait.
- ✓ He suggested going by train. — ✗ He suggested to go by train.
Verbs followed by an infinitive (to + verb)
These take to + the base verb. Common ones are want, need, decide, hope, plan, agree, offer, promise, refuse, learn, manage, expect, afford, pretend, seem and choose.
- ✓ I want to leave. — ✗ I want leaving.
- ✓ We decided to wait. — ✗ We decided waiting.
- ✓ She agreed to help. — ✗ She agreed helping.
- ✓ They can't afford to move. — ✗ They can't afford moving.
Infinitives also follow adjectives: It's hard to explain, I'm glad to help, She was quick to notice.
Verbs that take either form
After begin, start, continue, like, love, hate, prefer, bother and can't bear, both forms are correct and mean essentially the same thing.
- ✓ It started raining. = ✓ It started to rain.
- ✓ I love cooking. = ✓ I love to cook.
One caveat: English avoids two -ing forms back to back, so in a continuous tense the infinitive wins — It's starting to rain, not It's starting raining.
Verbs that change meaning: remember, stop, try, regret
This is where most mistakes happen, because both forms are grammatical but mean different things. As a pattern, the gerund points backwards to something already done, while the infinitive points forwards to a task or purpose.
- remember — I remembered to lock the door (I didn't forget the task) vs I remember locking the door (I have a memory of doing it).
- forget — Don't forget to call (a task ahead) vs I'll never forget meeting her (a past memory).
- stop — He stopped smoking (he quit the habit) vs He stopped to smoke (he paused in order to smoke).
- try — Try to reach the shelf (make the effort) vs Try standing on a chair (experiment with a solution).
- regret — We regret to inform you… (sorry about what we're about to say) vs I regret telling him (sorry about what I already did).
- mean — I didn't mean to upset you (intend) vs This job means working weekends (involves).
- go on — She went on to win gold (moved to the next thing) vs She went on talking (continued the same thing).
Always use a gerund after a preposition
Prepositions — in, on, at, of, about, for, without, after, before — are always followed by a gerund, never an infinitive.
- ✓ She's good at drawing. — ✗ She's good at to draw.
- ✓ He left without saying goodbye. — ✗ He left without to say goodbye.
- ✓ Thanks for waiting. — ✗ Thanks for to wait.
The classic trap is the word to, which is sometimes a preposition and sometimes part of an infinitive. In look forward to, be used to, get used to and object to, the to is a preposition — so a gerund follows:
- ✓ I look forward to hearing from you. — ✗ I look forward to hear from you.
- ✓ I'm used to working late. — ✗ I'm used to work late.
A quick test: if you can put a noun after the to (I look forward to the weekend), it's a preposition and you need the -ing form.
A memory trick that works
When a verb accepts either form, this rule of thumb is right more often than not: gerunds describe real, present or completed actions; infinitives describe potential, future or hypothetical ones. Compare I stopped smoking (a real thing I used to do) with I stopped to smoke (the purpose I paused for). It's also why enjoy, finish and admit — all about actual events — take gerunds, while want, hope and plan — all about things not yet real — take infinitives.
US and UK differences
Most of these rules are identical on both sides of the Atlantic, but a few genuinely differ:
- like + to: In British English, I like swimming means “I enjoy it,” while I like to swim before work often means “I make a point of it.” American English uses like to freely for plain enjoyment, so the distinction is weaker.
- need + gerund: The passive gerund after need is more common in British English — The car needs cleaning (= needs to be cleaned). The shirt wants ironing sounds natural in the UK and odd in the US.
- help: Both varieties allow help me carry and help me to carry, but American English drops the to more often.
The dialect form the car needs cleaned (dropping to be), heard in Scotland and parts of the US, is regional and best avoided in standard writing.
Two "rules" that are actually myths
You can split an infinitive. The old ban on putting a word between to and the verb — the reason some people flinch at to boldly go — has no basis in English grammar. It was borrowed from Latin, where an infinitive is a single word and literally cannot be split. To really understand and to slowly walk away are perfectly correct, and often clearer than the stiff alternatives.
You don't always need a possessive before a gerund. Sticklers insist on Do you mind my asking? over Do you mind me asking? The possessive is a shade more formal, but the object form is standard, natural English and has been for centuries. Use whichever suits the register.
Frequently Asked Questions
How do you know whether to use a gerund or an infinitive?
There's no single rule — the first verb decides. Learn the common lists: enjoy, avoid, finish and mind take gerunds; want, decide, hope and agree take infinitives. After any preposition, always use a gerund. When both are possible, remember that gerunds usually describe real or completed actions and infinitives describe future or potential ones.
Is it "look forward to hearing" or "look forward to hear"?
“Look forward to hearing” is correct. In this phrase, to is a preposition, not part of an infinitive, so it must be followed by the -ing form. A quick test: you can say “I look forward to the weekend,” which proves to takes a noun or gerund here — never the base verb “hear.”
What is the difference between "stop smoking" and "stop to smoke"?
They mean opposite things. “He stopped smoking” uses a gerund and means he quit the habit — smoking is what stopped. “He stopped to smoke” uses an infinitive of purpose and means he paused whatever he was doing in order to have a cigarette. Stop is one of several verbs whose meaning flips with the form.
Which verbs can be followed by both a gerund and an infinitive?
Verbs like begin, start, continue, like, love, hate and prefer take either form with virtually no change in meaning. A separate group — remember, forget, stop, try, regret, mean and go on — accepts both but changes meaning: the gerund refers back to a past action, while the infinitive points forward to a task or purpose.
Is it wrong to split an infinitive?
No. The idea that you can never put a word between to and the verb — as in “to boldly go” — is a myth imported from Latin grammar, where an infinitive is a single word. In English, splitting an infinitive is fully correct and often clearer: “to really understand” reads better than the stiff alternatives.