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.
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.
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.
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.
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.
Infinitives also follow adjectives: It's hard to explain, I'm glad to help, She was quick to notice.
After begin, start, continue, like, love, hate, prefer, bother and can't bear, both forms are correct and mean essentially the same thing.
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.
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.
Prepositions — in, on, at, of, about, for, without, after, before — are always followed by a gerund, never an infinitive.
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:
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.
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.
Most of these rules are identical on both sides of the Atlantic, but a few genuinely differ:
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.
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.
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.
“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.”
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.
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.
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.
