Forms of the Subject in Grammar


Various grammatical forms can function as subjects in sentences. The subject is most often a noun phrase, but it can also be a noun clause, or rarely, a prepositional phrase. Here is a table with examples.

Forms of the Subject
Noun phraseThe truth is out there.
Gerund phraseListening is better than speaking.
Infinitive phraseTo live is to hope.
Noun clauseWhat you want may not be what you need.
Prepositional phraseAt night is when I work best.
Implied subject(You) wait here, please.
Dummy subjectIt is impossible to predict the future.

Forms of the subject

Three main grammatical forms can function as the subject in a sentence or a clause.

  1. Noun phrases
  2. Noun clauses
  3. Prepositional phrases

Noun phrases include gerund and infinitive phrases, and implied and dummy subjects.

  • Noun phrase: Cats are kind and loving creatures.
  • Gerund phrase: Cycling is a great form of exercise.
  • Infinitive phrase: To know him is to love him.
  • Noun clause: What we found was a crystal.
  • Prepositional phrase: At home is where she’s happy.
  • Implied subject: (You) sit down!
  • Dummy subject: It is raining again.

In this article, we discuss how these different grammatical forms function as subjects.

Noun phrase as subject

Most often, a noun phrase is the subject in a sentence. A noun phrase comprises a noun or a pronoun and other words that modify it to together form a complete subject.

  • Anita has just quit her job as an analyst.
  • My cat would purr as loudly as a motorcycle engine.
  • They like to plan for the future.
  • A nice young man showed us the way to the station.
  • The woman who stole my car has been arrested.

Gerund as subject

A gerund (e.g., singing, dancing, running) or gerund phrase can act as the subject in a sentence. (A gerund is an -ing verb form that functions as a noun.)

  • Jogging is good for health.
  • Dancing in the rain is one of Lulu’s favorite pastimes.
  • Being a teacher is like being a parent to the world’s children.

We use gerunds to speak of activities, hobbies, and interests (Singing is my passion).

Infinitive as subject

An infinitive (e.g., to be, to sing, to dance) can perform the functions of a noun. Thus, the subject of a sentence can be an infinitive or infinitive phrase.

  • To err is human.
  • To dance in the rain is to be happy.
  • To be a teacher is to be a parent to the world’s children.

Using an infinitive instead of a gerund as the subject of a sentence conveys a more literary, formal tone.

  • Less formal: Seeing is believing.
  • More formal: To see is to believe.

Implied subject

In some sentences, the subject isn’t explicitly stated but is clear from context. For example, in commands and requests (which have an imperative structure), the subject is the pronoun “you.”

  • (You) shut that door before the zombies get in.
  • (You) don’t just stand there—do something!
  • (You) pass the pepper, please.

The subject may also be implied when a thought isn’t fully expressed in a sentence but is clear from context.

  • “Did you mow the lawn?”
    “Yes (I mowed the lawn).”

Dummy or fake subject

The subject you find in the structure of a sentence is sometimes not its real subject but a dummy subject (also called a fake, artificial, or empty subject). We often use it and there as dummy subjects.

  • It has been raining since morning.
  • It is nine in the evening, and Farley is still at work.
  • It is important to be grammatically correct but not as important as being kind to others.
  • There are three ways to solve this problem.

The dummy subject is often used to speak of weather, time, etc. (It’s snowing). Nevertheless, in formal writing, such as a thesis or a job application, where a direct style is preferred, avoid using dummy subjects when you can provide a real subject instead. (Compare “There are experiments we conducted” with “We conducted experiments.”)

Noun clause as subject

Sometimes, the subject isn’t just a word or a phrase but an embedded noun clause. (A noun clause has its own internal subject and verb, which together function as the subject of the sentence.) Such clauses start with words like what, that, and who.

  • What I really want is freedom.
  • Whoever invented this device is a genius.
  • Where I lay my head is home.
  • That there is no way out of this situation is clear to all of us.

The subject in a cleft sentence helps the object provide new information. Thus, the focus shifts from subject to object.

  • What she needs is some peace and quiet.
    This structure places focus on the object (some peace and quiet) rather than the subject.

Prepositional phrase as subject

It is possible for a prepositional phrase to function as the subject in a sentence.

  • After dinner is when we go for a walk.
    preposition = after; prepositional phrase = after dinner = subject
  • In the park is where you should exercise, instead of in a room.

Prepositional phrases as subjects are more common in speech than in writing.

  • “When can I call you?”
    After six should work.”

Usage guide

Remember that the subject is what the sentence is about. Choosing one subject over another can help you control focus in the sentence.

How you construct a sentence also affects its tone. Using an infinitive as subject can convey a more literary tone (To live is to wonder why). Noun clauses can move the focus to the object in a sentence (What we need is a miracle). Prepositional phrases as subjects are seen more often in speech than in writing (After six is perfect), as is the implied subject ([You] please wait). Sentences with dummy subjects (There are many papers that investigate this phenomenon) are best avoided in academic and business writing (Better: Many papers investigate this phenomenon).

Quick Quiz

Which of these contains a grammatically correct subject?
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All done!
Which of these contains a grammatically correct subject?
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All done!
Which of these contains a subject?
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All done!

Did You Know?

The 24-hour clock is preferred in situations where confusion between “a.m.” and “p.m.” could result in dangerous or expensive mistakes.
Know more:Time of Day: How to Write Correctly