Gerunds and Infinitives
Gerunds (the -ing form of a verb used as a noun: swimming, reading) and infinitives (to plus the base verb: to swim, to read) can both follow certain verbs, but English doesn't let you use either one interchangeably after every verb — some verbs demand a gerund, some demand an infinitive, some accept either with no change in meaning, and a few accept either with a real difference in meaning, and there's no single rule that predicts which category a given verb falls into.
Verbs that take only a gerund
Verbs like enjoy, avoid, consider, finish, mind, and suggest are followed by a gerund, never a bare infinitive: She enjoys swimming (not 'enjoys to swim'). He avoided answering the question (not 'avoided to answer'). There's no consistent semantic reason these particular verbs require a gerund rather than an infinitive — it's a lexical fact about each individual verb that has to be learned rather than derived from a general rule.
Verbs that take only an infinitive
Verbs like want, decide, plan, hope, agree, and promise are followed by an infinitive, never a gerund: She wants to leave (not 'wants leaving'). They decided to wait (not 'decided waiting'). As with the gerund-only verbs, this is a fact about specific verbs rather than a predictable pattern based on meaning, which is exactly why English learners are typically taught these as memorized lists rather than as a rule with clean logical boundaries.
Verbs that take either, with no real difference in meaning
A smaller set of verbs, including start, begin, continue, and like, accept both forms with essentially the same meaning: It started raining and It started to rain are functionally interchangeable, as are She likes swimming and She likes to swim. In careful usage, some subtle stylistic or regional preferences exist (British English leans slightly more toward the gerund in some of these cases), but neither choice is considered incorrect.
Verbs where the choice actually changes the meaning
A distinct, smaller category of verbs genuinely changes meaning depending on whether a gerund or infinitive follows: stop, remember, forget, and try are the classic examples. I stopped smoking means I quit the habit of smoking; I stopped to smoke means I paused another activity in order to smoke. I remembered locking the door means I recall the act of locking it (it already happened); I remembered to lock the door means I didn't forget to do it (a future or intended action). This category is worth extra attention precisely because using the wrong form here doesn't just sound unnatural — it actually communicates a different meaning than the speaker intended.
Gerunds and infinitives after prepositions
After a preposition, English requires a gerund, never a bare infinitive: She's interested in learning (not 'in to learn'). He's good at solving problems (not 'at to solve'). This is one of the more reliable, rule-governed corners of the whole gerund/infinitive system, since it applies consistently across virtually every preposition-plus-verb construction in English.
Gerunds and infinitives as sentence subjects
Both gerunds and infinitives can open a sentence as its subject, generally interchangeably in meaning though with a slight difference in register: Swimming is good exercise and To swim is good exercise are both grammatical, with the gerund version reading as somewhat more natural and common in everyday speech, and the infinitive version reading as slightly more formal or literary.
Why this system exists at all in English
Historically, the gerund descends from the Old English verbal noun ending in -ing, while the infinitive descends from a separate verb form entirely, and the two systems developed largely independently before converging into the modern situation where individual verbs each have their own idiosyncratic preference for one, the other, both, or a meaning-changing choice between them — this fragmented, historically layered system is exactly why the rules resist tidy generalization and are typically taught, especially to language learners, as memorized verb-by-verb patterns rather than a single unified principle.
A practical strategy for learning which pattern a verb follows
Because there's no fully reliable shortcut, the most practical approach is exposure and memorization through reading and listening to a large volume of real English, paying attention to which pattern recurs after specific common verbs, supplemented by reference lists (widely available in grammar and ESL resources) that group verbs by which category — gerund-only, infinitive-only, either, or meaning-changing — they belong to.
Gerunds and infinitives after adjectives
Certain adjectives are typically followed by an infinitive rather than a gerund: happy to help, eager to learn, ready to leave, difficult to explain. Others pair naturally with a preposition-plus-gerund construction instead: interested in helping, good at explaining. As with verbs, which pattern a given adjective takes is largely a fixed, memorized fact about that specific adjective rather than something derivable from a general grammatical principle.
The 'for' and 'of' patterns in infinitive constructions
Infinitive phrases sometimes need an explicit subject introduced by 'for': It's important for her to arrive early. In a smaller set of constructions involving personal-quality adjectives (kind, nice, rude, foolish), 'of' introduces the subject instead: It was kind of him to help. Mixing these up ('It's important of her to arrive early') produces a sentence that reads as clearly wrong to a fluent speaker, even though the underlying logic — introducing the infinitive's own subject — is the same in both patterns.
Gerunds functioning as objects of a sentence
Beyond following specific verbs, gerunds can serve as the direct object of an entire sentence in ways an infinitive sometimes can't substitute for as naturally: Reading calms her down treats 'reading' as the subject, while She enjoys reading treats it as the object — in both cases, the gerund is functioning exactly like an ordinary noun would, which is the defining feature that separates a gerund from a verb used in its ordinary verbal role.
How this pattern compares across related languages
Many languages that are otherwise grammatically similar to English handle the gerund/infinitive distinction quite differently — some languages don't distinguish between the two forms at all after a given verb, using only an infinitive-equivalent construction universally, which is part of why this specific area of English grammar is frequently cited as one of the more persistently difficult points for adult language learners, even those who are otherwise highly fluent.
A worked comparison of near-synonymous verbs with different patterns
Comparing near-synonyms highlights how arbitrary the assignment can feel: 'enjoy' takes only a gerund (enjoy swimming) while its close synonym 'like' takes either (like swimming or like to swim), and 'want,' which expresses a related but distinct kind of desire, takes only an infinitive (want to swim). No semantic rule predicts this pattern from the verbs' meanings alone, which is exactly why language learners and even attentive native speakers occasionally have to consciously recall which category a specific verb belongs to rather than reasoning it out from first principles.
Passive gerunds and passive infinitives
Both gerunds and infinitives can appear in a passive form, adding another layer to an already complex system: being chosen (passive gerund), to be chosen (passive infinitive). She dislikes being interrupted uses a passive gerund correctly after 'dislikes,' following the same gerund-only pattern as the active form (dislikes interrupting someone), simply with the roles of subject and object reversed to reflect the passive construction.
A closing note on approaching this system practically
Because so much of this pattern resists tidy generalization, the most efficient path for both learners and careful writers is treating verb-plus-gerund and verb-plus-infinitive pairings as a vocabulary item to memorize alongside each verb's meaning, the same way irregular plurals or irregular past tenses are memorized rather than derived from a rule, and consulting a reference list whenever a specific verb's pattern is genuinely uncertain.
Frequently asked questions
Is there a rule for which verbs take gerunds versus infinitives?
Not a fully reliable one — this is largely a lexical, verb-by-verb fact in English rather than something predictable from a general grammatical principle, which is why it's typically taught through memorized verb groupings rather than a single rule.
Does 'stop to do something' always mean the same as 'stop doing something'?
No — these have genuinely different meanings. 'Stop doing' means ceasing an ongoing action; 'stop to do' means pausing one activity in order to begin a different one, making this one of the few gerund/infinitive choices that actually changes a sentence's meaning rather than just its style.
Why does 'interested in learning' use a gerund instead of an infinitive?
Because 'in' is a preposition, and English requires a gerund after any preposition, never a bare infinitive — this rule holds consistently regardless of which specific preposition or verb is involved.
Why does 'avoid' take a gerund but 'want' take an infinitive?
There's no reliable semantic explanation — this is simply a lexical fact about each individual verb in English, learned through exposure and memorization rather than derived from any consistent underlying grammatical principle. Grouping verbs into reference lists by category remains the most practical study strategy available. Over time, repeated exposure through reading tends to make the correct pattern feel automatic.