00 / Non-finite Verbs
Gerunds and infinitives
Gerunds and infinitives can function as nouns within a sentence, acting as the subject or the object of a verb. While gerunds are more common as subjects in daily speech, infinitives often appear in formal or poetic contexts.
B1Intermediate
01 / Gerunds and Infinitives as Subjects
When an action is the main topic of a sentence, we use the gerund (-ing form) or the infinitive (to + verb) as the subject. The gerund is the standard choice for general activities, while the infinitive sounds more formal or abstract.
- Swimming is good exercise. (Common/Natural)
- To swim in the ocean requires strength. (Formal/Literary)
02 / Sentence Structure
Gerund/Infinitive + Singular Verb + Complement
Both forms take a singular verb. Even if the gerund or infinitive is followed by a plural noun, the main verb remains singular because the subject is the action itself.
03 / Usage in Context
04 / Common mistakes
Eat vegetables is important for your health.
Eating vegetables is important for your health.
A base verb cannot act as a subject; you must use the gerund or infinitive form.
Playing video games are my favorite hobby.
Playing video games is my favorite hobby.
The subject is the act of 'playing' (singular), not the 'games' (plural).
05 / Gerund vs. Infinitive Subjects
In modern English, use the gerund for almost all subject positions unless you are writing formal poetry or legal texts.
| Feature | Gerund (-ing) | Infinitive (to + verb) |
|---|---|---|
| Register | Neutral and common | Formal or philosophical |
| Frequency | Very high | Low (mostly in literature/proverbs) |
| Example | Running is fun. | To run is to live. |
06 / Practice
___ (travel) around the world is my ultimate dream.
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Answer: Traveling
Why: The gerund form 'Traveling' (or 'Travelling') acts as the subject of the sentence to describe a general activity.
To ___ (err) is human; to forgive is divine.
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Answer: err
Why: This famous proverb uses the infinitive 'To err' as a subject to create a formal, philosophical tone.
Correct the error: 'Watch movies helps me relax after work.'
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Answer: Watching movies helps me relax after work.
Why: The subject must be a gerund or infinitive; the base verb 'watch' cannot function as a noun.