I. Gerunds and Infinitives: Introduction and Review

Gerunds and infinitives are two of the most important non-finite verb forms in English. They allow us to use verbs as nouns, adjectives, or adverbs, which is essential for building complex, natural sentences. Understanding their functions and the contexts in which each is used is a cornerstone of advanced grammar.

1. What Are They? (Form and Basic Definition)

• Gerund: The -ing form of a verb that functions as a noun.
  e.g., “Swimming is my favourite sport.” (Here, “swimming” is the subject of the sentence.)
• Infinitive: The to + base verb form that functions as a noun, adjective, or adverb.
  e.g., “I want to travel the world.” (Here, “to travel” is the object of the verb “want”.)
• Bare Infinitive: The base form of the verb without “to”. Used after modals (can, must), certain verbs of perception (see, hear), and let / make.
  e.g., “She must go now.” / “I saw him leave.”

2. Functions of Gerunds

Because gerunds function as nouns, they can occupy many of the same positions in a sentence as a regular noun.

• Subject of a sentence:
  “Reading improves your vocabulary.”
• Object of a verb:
  “She enjoys playing the piano.”
• Object of a preposition:
  “He is afraid of failing the exam.” (Always use a gerund after a preposition.)
• Subject complement (predicate noun):
  “Her biggest passion is dancing.”
• After certain possessive adjectives:
  “Do you mind my opening the window?”

3. Functions of Infinitives

Infinitives are more flexible; they can act as nouns, adjectives, or adverbs, which gives them a wider range of uses.

• As a noun (subject or object):
  “To learn a new language takes time.” (Subject)
  “They decided to postpone the trip.” (Object)
• As an adjective (modifying a noun):
  “I need a book to read on the flight.” (Describes the book.)
• As an adverb (expressing purpose, result, or reason):
  “She went to the store to buy milk.” (Purpose – the most common adverbial use.)
• After certain adjectives:
  “It is important to be on time.”
• With “too” and “enough”:
  “The box is too heavy to lift.” / “She is old enough to vote.”

4. Verbs That Take Gerunds vs. Infinitives (The Critical Choice)

The most challenging aspect of gerunds and infinitives is that certain verbs must be followed by one or the other. Some verbs even change meaning depending on which form you use.

A. Verbs Followed by Gerunds (Common List)

• admit, avoid, consider, deny, enjoy, finish, imagine, keep, mind, miss, postpone, practise, quit, recall, recommend, resist, risk, suggest, tolerate.
• Example: “She avoided answering the question.”

B. Verbs Followed by Infinitives (Common List)

• afford, agree, appear, arrange, ask, choose, decide, expect, hope, learn, manage, need, offer, plan, prepare, promise, refuse, seem, want, wish, would like.
• Example: “They agreed to help us.”

C. Verbs That Change Meaning (Gerund vs. Infinitive)

• Remember / Forget / Regret – Gerund = remembering a past action; Infinitive = remembering to do a future action.
  “I remember locking the door.” (I recall doing it.)
  “I remembered to lock the door.” (I didn't forget my duty.)
• Stop – Gerund = cease an action; Infinitive = interrupt one action to do another.
  “He stopped smoking.” (He quit.)
  “He stopped to smoke.” (He paused to have a cigarette.)
• Try – Gerund = experiment with a method; Infinitive = make an effort (often difficult).
  “Try adding more salt.” (Experiment.)
  “Try to finish it by noon.” (Make an effort.)
• Go on – Gerund = continue the same action; Infinitive = proceed to a new action.
  “He went on talking for hours.” (Continued.)
  “He went on to talk about the next topic.” (Changed topics.)

5. Advanced Forms: Passive, Continuous, and Perfect

Both gerunds and infinitives have additional forms that express time and voice, adding nuance to your descriptions.

• Passive Gerund: being + V3 (emphasises the action happening to the subject).
  “She doesn't like being told what to do.”
• Perfect Gerund: having + V3 (emphasises that the gerund action happened before the main verb).
  “He was proud of having won the award.”
• Passive Infinitive: to be + V3.
  “He hopes to be chosen for the team.”
• Perfect Infinitive: to have + V3 (used after modals or certain verbs to indicate a past action).
  “She seems to have forgotten our meeting.” (The forgetting happened earlier.)
• Continuous Infinitive: to be + V-ing (emphasises an ongoing action).
  “He appears to be sleeping.”

Summary Table: Gerunds vs. Infinitives – Core Differences

6. Summary and Practical Tip

The choice between a gerund and an infinitive is often a matter of memorising the governing verb, the preposition, or the intended meaning. When in doubt, remember these core rules:

• If you need a noun after a preposition → use a gerund.
• If you are expressing a purpose (why?) → use the infinitive.
• If the main verb changes meaning (like stop, remember, forget) → pay close attention to whether you are talking about a past action (gerund) or a future duty/effort (infinitive).